“IEEE guide for the interpretation of gases generated in oil-immersed transformers," IEEE Std C57.104-2008 (Revision of IEEE Std C57.104-1991), pp. 1-36, Feb 2009


Mineral oil-filled electrical equipment in service - Guidance on the interpretation of dissolved and free gases analysis, 3rd ed. International Electrotechnical Commission, Sep 2015, no. IEC 60599-2015-09


ASTM, Standard Test Method for Analysis of Gases Dissolved in Electrical Insulating Oil by Gas Chromatography. ASTM International, 2017, no. ASTM D3612-02(2017)