APA

National Recreation Association, . (1936). The conduct of playgrounds: a practical guide for playground workers. New York: N.R.A.

Chicago

National Recreation Association, . 1936. The conduct of playgrounds: a practical guide for playground workers. New York: N.R.A.

Harvard

National Recreation Association, . (1936). The conduct of playgrounds: a practical guide for playground workers. New York: N.R.A.

MLA

National Recreation Association, . The conduct of playgrounds: a practical guide for playground workers. New York: N.R.A. 1936.