APA (7e ed.) Bronvermelding

Não informado. Topographic instructions of the United States Geological Survey. U.S. Department of the Interior.

Chicago (17e ed.) Bronvermelding

Não informado. Topographic Instructions of the United States Geological Survey. Washington: U.S. Department of the Interior.

MLA (8e ed.) Bronvermelding

Não informado. Topographic Instructions of the United States Geological Survey. U.S. Department of the Interior.

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