1. High Voltage Engineering: Fundamentals;Kuffel,2000
2. High-Voltage Test Techniques. Part 1: General Definitions and Test Requirements,2010
3. IEEE Standard for High-Voltage Testing Techniques,2013
4. Power Transformer. Part 1: General,2011
5. Power Transformer. Part 3: Insulation Level, Dielectric Tests and External Clearances in Air,2013