Butler, G. D. (1958). Recreation areas: Their design and equipment (2nd ed.). New York: Ronald Press.
Παραπομπή Chicago StyleButler, George D. Recreation Areas: Their Design and Equipment. 2nd ed. New York: Ronald Press, 1958.
Παραπομπή MLAButler, George D. Recreation Areas: Their Design and Equipment. 2nd ed. New York: Ronald Press, 1958.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.