APA (7th ed.) Citation

Hahn, J. L., Hader, B., & Hader, E. (1937). Who knows: A little primer. Houghton Mifflin Company.

Chicago Style (17th ed.) Citation

Hahn, Julia Letheld, Berta Hader, and Elmer Hader. Who Knows: A Little Primer. Boston ; New York ; Chicago ; Dallas ; Atlanta ; San Francisco: Houghton Mifflin Company, 1937.

MLA (8th ed.) Citation

Hahn, Julia Letheld, et al. Who Knows: A Little Primer. Houghton Mifflin Company, 1937.