GOST 18145-1981 Circuits at the interface C2 of the data transmission equipment with the terminals in the consequent data input-output. Nomenclature and technical requirements
GOST 23675-1979 Interface circuits C2 of data transmission system. Electric parameters
GOST 27232-1987 Interface of data transmission with physical lines. Basic parameters
GOST 27373-1987 history
1987GOST 27373-1987 Data transmission system signal conversion modulus for physical effects. Types and basic parameters