APA (7e ed.) Bronvermelding

Não informado. Outdoor Recreation Research. U.S. Department of the Interior, Bureau of Outdoor Recreation.

Chicago (17e ed.) Bronvermelding

Não informado. Outdoor Recreation Research. Washington: U.S. Department of the Interior, Bureau of Outdoor Recreation.

MLA (8e ed.) Bronvermelding

Não informado. Outdoor Recreation Research. U.S. Department of the Interior, Bureau of Outdoor Recreation.

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