High-pressure sodium vapour lamps (IEC 662 (1980) 1st edition and amendment 1 (1986) and amendment 2 (1987), modified); german version EN 60662:1989— 46 стр.
High-pressure sodium vapour lamps (IEC 60662:1980 and amendment 1:1986, amendment 2:1987 and amendment 3:1990, modified); German version EN 60662:1993— 49 стр.
High-pressure sodium vapour lamps (IEC 60662:1980 and amendment 1:1986, amendment 2:1987 and amendment 3:1990, modified); German version EN 60662:1993— 49 стр.