APA (7e ed.) Bronvermelding

Não informado. (1970). Copper abstracts. International Copper Development Council.

Chicago (17e ed.) Bronvermelding

Não informado. Copper Abstracts. Geneva, Suíça: International Copper Development Council, 1970.

MLA (8e ed.) Bronvermelding

Não informado. Copper Abstracts. International Copper Development Council, 1970.

Let op: Deze citaties zijn niet altijd 100% accuraat.