APA (7th ed.) Citation

Schaaf, W. L. (1963). Recreational mathematics, a guide to the literature (3d ed.). National Council of Teachers of Mathematics.

Chicago Style (17th ed.) Citation

Schaaf, William Leonard. Recreational Mathematics, a Guide to the Literature. 3d ed. Washington: National Council of Teachers of Mathematics, 1963.

MLA (9th ed.) Citation

Schaaf, William Leonard. Recreational Mathematics, a Guide to the Literature. 3d ed. National Council of Teachers of Mathematics, 1963.