Citazione APA

Betts, E. A., Welch, C. M., & Ernst, C. (1953). Time to play. American Book Company.

Stile di citazione Chicago

Betts, Emmett A., Carolyn M. Welch, e Clara Ernst. Time to Play. New York ; Cincinnati ; Chicago ; Boston ; Atlanta ; Dallas ; San Francisco: American Book Company, 1953.

Citazione MLA

Betts, Emmett A., et al. Time to Play. American Book Company, 1953.