Clawson, M., & Knetsch, J. L. (1966). Economics of outdoor recreation. Baltimore: John Hopkins Press.
Παραπομπή Chicago StyleClawson, Marion, and Jack L. Knetsch. Economics of Outdoor Recreation. Baltimore: John Hopkins Press, 1966.
Παραπομπή MLAClawson, Marion, and Jack L. Knetsch. Economics of Outdoor Recreation. Baltimore: John Hopkins Press, 1966.
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