Παραπομπή APA

Clawson, M., & Knetsch, J. L. (1975). Economics of outdoor recreation. Baltimore: The Johns Hopkins University Press.

Παραπομπή Chicago Style

Clawson, Marion, and Jack L. Knetsch. Economics of Outdoor Recreation. Baltimore: The Johns Hopkins University Press, 1975.

Παραπομπή MLA

Clawson, Marion, and Jack L. Knetsch. Economics of Outdoor Recreation. Baltimore: The Johns Hopkins University Press, 1975.

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