APA (7e ed.) Bronvermelding

Não informado. (1981). Energy and minerals resources. Business Publishers.

Chicago (17e ed.) Bronvermelding

Não informado. Energy and Minerals Resources. Silver Spring, Md: Business Publishers, 1981.

MLA (8e ed.) Bronvermelding

Não informado. Energy and Minerals Resources. Business Publishers, 1981.

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