1. International Standard ISO 60433:2005. Insulating Mineral Oil in Electrical Equipment. Guidance on Monitoring and Servicing.
2. International Standard ASTM D 971-99a–2004. Standard Ring Test for Determining the Surface Tension at an Oil-Water Interface.
3. Instructions for Determining the Optical Turbidity of Transformer Oil in Sealed Leads at 110 kV and Above, Power Transformers, and Shunt Reactors [in Russian], JSC “Énergeticheskie tekhnologii,” Moscow (2007), Confirmed by JSC RAO “EÉS Rossii,” June 21, 2007.
4. RD 34.45-51.300–97. Amount and Standards for Tests of Electrical Equipment [in Russian], NTs “Énas,” Moscow (2004).
5. State Standard GOST 20284–74 (ISO 2049). Petroleum Products. Method for Determining Color on the TsNT (CIE) Colorimeter [in Russian].