Household and similar electrical appliances - Safety - Part 2-51: Particular requirements for stationary circulation pumps for heating and service water installations (IEC 60335-2-51:2002 + A1:2008 + A2:2011) (english version)
Liquid pumps and installation - General terms, definitions, quantities, letter symbols and units - Part 2: Pumping System (multilingual version: en/fr/ru/de) (ISO 17769-2:2012)
Liquid pumps and installation - General terms, definitions, quantities, letter symbols and units - Part 1: Liquid pumps (multilingual version: en/fr/ru/de) (ISO 17769-1:2012)