APA (7e ed.) Bronvermelding

Não informado. (2011). U.S. Geological Survey Bulletin. U.S. Department of the Interior, Geological Survey.

Chicago (17e ed.) Bronvermelding

Não informado. U.S. Geological Survey Bulletin. Washington: U.S. Department of the Interior, Geological Survey, 2011.

MLA (8e ed.) Bronvermelding

Não informado. U.S. Geological Survey Bulletin. U.S. Department of the Interior, Geological Survey, 2011.

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