APA (7e ed.) Bronvermelding

Butler, G. D. (1936). Playgrounds, their administration and operation: National recreation association. A.S. Barnes.

Chicago (17e ed.) Bronvermelding

Butler, George D. Playgrounds, Their Administration and Operation: National Recreation Association. New York: A.S. Barnes, 1936.

MLA (8e ed.) Bronvermelding

Butler, George D. Playgrounds, Their Administration and Operation: National Recreation Association. A.S. Barnes, 1936.