Chapter 1 Global Ultrafast Recovery Rectifier Market Overview

1.1 Introduction
1.2 Taxonomy
1.2.1 By Product Type & End User
1.2.2 By Region
1.3 Drivers for Ultrafast Recovery Rectifier Market
1.4 Restraints for Ultrafast Recovery Rectifier Market
1.5 Opportunities for Ultrafast Recovery Rectifier Market
1.6 Trends for Ultrafast Recovery Rectifier Market
1.7 COVID-19 Impact Assessment on Ultrafast Recovery Rectifier Industry
1.8 Macro-economic Factors
1.9 Regulatory Framework
1.10 Pricing Analysis by Region, 2022
1.11 Opportunity Map Analysis
1.12 Opportunity Orbits
1.13 Market Investment Feasibility Index
1.14 PEST Analysis
1.15 PORTERS Five Force Analysis
1.16 Go to Market Strategy
1.17 Value Chain Analysis
1.18 Cost Structure Analysis
1.19 Regional Market Share and BPS Analysis

Chapter 2 Global Ultrafast Recovery Rectifier Market Overview

2.1 Global Ultrafast Recovery Rectifier Market by Product Type
2.1.1 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2030)
2.1.2 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Product Type in 2019
2.1.3 Global Ultrafast Recovery Rectifier Market Attractiveness Analysis by Product Type, (2015-2022)
2.2 Global Ultrafast Recovery Rectifier Market by End User
2.2.1 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2030)
2.2.2 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by End User in 2019
2.2.3 Global Ultrafast Recovery Rectifier Market Attractiveness Analysis by End User, (2015-2022)
2.3 Global Ultrafast Recovery Rectifier Market by Region
2.3.1 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2030)
2.3.2 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Region in 2019
2.3.3 Global Ultrafast Recovery Rectifier Market Attractiveness Analysis by Region, (2015-2022)
2.4 Global Ultrafast Recovery Rectifier Market Outlook (2015-2030)
2.4.1 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2015-2022)
2.4.2 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2022-2030)
2.5 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Regions
2.5.1 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2022)
2.5.2 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2022-2030)
2.6 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Product Type
2.6.1 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2022)
2.6.2 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2022-2030)
2.7 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by End User
2.7.1 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2022)
2.7.2 Global Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2022-2030)
2.8 Global Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate Comparison (2014-2030)
2.8.1 Global Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Region
2.8.2 Global Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Product Type
2.8.3 Global Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by End User
2.9 Global Ultrafast Recovery Rectifier Market Share Comparison (2015-2030)
2.9.1 Global Ultrafast Recovery Rectifier Market Share by Region
2.9.2 Global Ultrafast Recovery Rectifier Market Share by Product Type
2.9.3 Global Ultrafast Recovery Rectifier Market Share by End User

Chapter 3 North America Ultrafast Recovery Rectifier Market Overview

3.1 North America Ultrafast Recovery Rectifier Market by Product Type
3.1.1 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2030)
3.1.2 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Product Type in 2019
3.1.3 North America Ultrafast Recovery Rectifier Market Attractiveness Analysis by Product Type, (2015-2022)
3.2 North America Ultrafast Recovery Rectifier Market by End User
3.2.1 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2030)
3.2.2 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by End User in 2019
3.2.3 North America Ultrafast Recovery Rectifier Market Attractiveness Analysis by End User, (2015-2022)
3.3 North America Ultrafast Recovery Rectifier Market by Region
3.3.1 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2030)
3.3.2 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Region in 2019
3.3.3 North America Ultrafast Recovery Rectifier Market Attractiveness Analysis by Region, (2015-2022)
3.4 North America Ultrafast Recovery Rectifier Market Outlook (2015-2030)
3.4.1 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2015-2022)
3.4.2 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2022-2030)
3.5 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Regions
3.5.1 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2022)
3.5.2 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2022-2030)
3.6 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Product Type
3.6.1 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2022)
3.6.2 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2022-2030)
3.7 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by End User
3.7.1 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2022)
3.7.2 North America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2022-2030)
3.8 North America Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate Comparison (2014-2030)
3.8.1 North America Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Region
3.8.2 North America Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Product Type
3.8.3 North America Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by End User
3.9 North America Ultrafast Recovery Rectifier Market Share Comparison (2015-2030)
3.9.1 North America Ultrafast Recovery Rectifier Market Share by Region
3.9.2 North America Ultrafast Recovery Rectifier Market Share by Product Type
3.9.3 North America Ultrafast Recovery Rectifier Market Share by End User

Chapter 4 Europe Ultrafast Recovery Rectifier Market Overview

4.1 Europe Ultrafast Recovery Rectifier Market by Product Type
4.1.1 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2030)
4.1.2 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Product Type in 2019
4.1.3 Europe Ultrafast Recovery Rectifier Market Attractiveness Analysis by Product Type, (2015-2022)
4.2 Europe Ultrafast Recovery Rectifier Market by End User
4.2.1 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2030)
4.2.2 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by End User in 2019
4.2.3 Europe Ultrafast Recovery Rectifier Market Attractiveness Analysis by End User, (2015-2022)
4.3 Europe Ultrafast Recovery Rectifier Market by Region
4.3.1 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2030)
4.3.2 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Region in 2019
4.3.3 Europe Ultrafast Recovery Rectifier Market Attractiveness Analysis by Region, (2015-2022)
4.4 Europe Ultrafast Recovery Rectifier Market Outlook (2015-2030)
4.4.1 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2015-2022)
4.4.2 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2022-2030)
4.5 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Regions
4.5.1 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2022)
4.5.2 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2022-2030)
4.6 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Product Type
4.6.1 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2022)
4.6.2 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2022-2030)
4.7 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by End User
4.7.1 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2022)
4.7.2 Europe Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2022-2030)
4.8 Europe Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate Comparison (2014-2030)
4.8.1 Europe Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Region
4.8.2 Europe Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Product Type
4.8.3 Europe Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by End User
4.9 Europe Ultrafast Recovery Rectifier Market Share Comparison (2015-2030)
4.9.1 Europe Ultrafast Recovery Rectifier Market Share by Region
4.9.2 Europe Ultrafast Recovery Rectifier Market Share by Product Type
4.9.3 Europe Ultrafast Recovery Rectifier Market Share by End User

Chapter 5 Asia Pacific Ultrafast Recovery Rectifier Market Overview

5.1 Asia Pacific Ultrafast Recovery Rectifier Market by Product Type
5.1.1 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2030)
5.1.2 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Product Type in 2019
5.1.3 Asia Pacific Ultrafast Recovery Rectifier Market Attractiveness Analysis by Product Type, (2015-2022)
5.2 Asia Pacific Ultrafast Recovery Rectifier Market by End User
5.2.1 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2030)
5.2.2 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by End User in 2019
5.2.3 Asia Pacific Ultrafast Recovery Rectifier Market Attractiveness Analysis by End User, (2015-2022)
5.3 Asia Pacific Ultrafast Recovery Rectifier Market by Region
5.3.1 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2030)
5.3.2 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Region in 2019
5.3.3 Asia Pacific Ultrafast Recovery Rectifier Market Attractiveness Analysis by Region, (2015-2022)
5.4 Asia Pacific Ultrafast Recovery Rectifier Market Outlook (2015-2030)
5.4.1 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2015-2022)
5.4.2 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2022-2030)
5.5 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Regions
5.5.1 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2022)
5.5.2 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2022-2030)
5.6 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Product Type
5.6.1 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2022)
5.6.2 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2022-2030)
5.7 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by End User
5.7.1 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2022)
5.7.2 Asia Pacific Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2022-2030)
5.8 Asia Pacific Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate Comparison (2014-2030)
5.8.1 Asia Pacific Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Region
5.8.2 Asia Pacific Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Product Type
5.8.3 Asia Pacific Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by End User
5.9 Asia Pacific Ultrafast Recovery Rectifier Market Share Comparison (2015-2030)
5.9.1 Asia Pacific Ultrafast Recovery Rectifier Market Share by Region
5.9.2 Asia Pacific Ultrafast Recovery Rectifier Market Share by Product Type
5.9.3 Asia Pacific Ultrafast Recovery Rectifier Market Share by End User

Chapter 6 South America Ultrafast Recovery Rectifier Market Overview

6.1 South America Ultrafast Recovery Rectifier Market by Product Type
6.1.1 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2030)
6.1.2 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Product Type in 2019
6.1.3 South America Ultrafast Recovery Rectifier Market Attractiveness Analysis by Product Type, (2015-2022)
6.2 South America Ultrafast Recovery Rectifier Market by End User
6.2.1 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2030)
6.2.2 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by End User in 2019
6.2.3 South America Ultrafast Recovery Rectifier Market Attractiveness Analysis by End User, (2015-2022)
6.3 South America Ultrafast Recovery Rectifier Market by Region
6.3.1 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2030)
6.3.2 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Region in 2019
6.3.3 South America Ultrafast Recovery Rectifier Market Attractiveness Analysis by Region, (2015-2022)
6.4 South America Ultrafast Recovery Rectifier Market Outlook (2015-2030)
6.4.1 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2015-2022)
6.4.2 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2022-2030)
6.5 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Regions
6.5.1 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2022)
6.5.2 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2022-2030)
6.6 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Product Type
6.6.1 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2022)
6.6.2 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2022-2030)
6.7 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by End User
6.7.1 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2022)
6.7.2 South America Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2022-2030)
6.8 South America Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate Comparison (2014-2030)
6.8.1 South America Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Region
6.8.2 South America Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Product Type
6.8.3 South America Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by End User
6.9 South America Ultrafast Recovery Rectifier Market Share Comparison 2015-2030
6.9.1 South America Ultrafast Recovery Rectifier Market Share by Region
6.9.2 South America Ultrafast Recovery Rectifier Market Share by Product Type
6.9.3 South America Ultrafast Recovery Rectifier Market Share by End User

Chapter 7 MEA Ultrafast Recovery Rectifier Market Overview

7.1 MEA Ultrafast Recovery Rectifier Market by Product Type
7.1.1 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2030)
7.1.2 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Product Type in 2019
7.1.3 MEA Ultrafast Recovery Rectifier Market Attractiveness Analysis by Product Type, (2015-2022)
7.2 MEA Ultrafast Recovery Rectifier Market by End User
7.2.1 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2030)
7.2.2 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by End User in 2019
7.2.3 MEA Ultrafast Recovery Rectifier Market Attractiveness Analysis by End User, (2015-2022)
7.3 MEA Ultrafast Recovery Rectifier Market by Region
7.3.1 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2030)
7.3.2 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Market Share by Region in 2019
7.3.3 MEA Ultrafast Recovery Rectifier Market Attractiveness Analysis by Region, (2015-2022)
7.4 MEA Ultrafast Recovery Rectifier Market Outlook (2015-2030)
7.4.1 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2015-2022)
7.4.2 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) (2022-2030)
7.5 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Regions
7.5.1 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2015-2022)
7.5.2 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Region (2022-2030)
7.6 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by Product Type
7.6.1 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2015-2022)
7.6.2 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by Product Type (2022-2030)
7.7 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) by End User
7.7.1 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2015-2022)
7.7.2 MEA Ultrafast Recovery Rectifier Market Value (US$ Mn) and Volume (Units) Comparison by End User (2022-2030)
7.8 MEA Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate Comparison (2014-2030)
7.8.1 MEA Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Region
7.8.2 MEA Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by Product Type
7.8.3 MEA Ultrafast Recovery Rectifier Market Y-o-Y Growth Rate by End User
7.9 MEA Ultrafast Recovery Rectifier Market Share Comparison (2015-2030)
7.9.1 MEA Ultrafast Recovery Rectifier Market Share by Region
7.9.2 MEA Ultrafast Recovery Rectifier Market Share by Product Type
7.9.3 MEA Ultrafast Recovery Rectifier Market Share by End User

Chapter 8 Global Ultrafast Recovery Rectifier Market Company Profiles

8.1 Market Competition Scenario Analysis, By Company
8.2 Competitor Landscape
8.3 Company Share Analysis
8.4 Company Profiles
8.4.1 Company
8.4.1.1 Company Overview
8.4.1.2 Business Description
8.4.1.3 Product Portfolio
8.4.1.4 Key Financials
8.4.1.5 Key Developments
8.4.1.6 SWOT Analysis

Companies Included:
Central Semiconductor
Diodes Incorporated
Infineon
IXYS
Littelfuse
Micro Commercial Components
Microsemi
NXP
ON Semiconductor
ROHM
Semtech
STMicroeletronics
Surge
Vishay
WeEn Semiconductors

Chapter 9 Methodology and Data Source

9.1 Research Approach/ Methodology
9.2 Market Size Estimation
9.3 Market Breakdown and Data Triangulation
9.4 Data Source
9.4.1 Secondary Sources
9.4.2 Primary Sources