APA Citation

Spillman, W. J., & Lang, E. (1924). The law of diminishing returns. New York: World Book Company.

Chicago Style Citation

Spillman, W. J., and Emil Lang. The Law of Diminishing Returns. New York: World Book Company, 1924.

MLA Citation

Spillman, W. J., and Emil Lang. The Law of Diminishing Returns. New York: World Book Company, 1924.

Warning: These citations may not always be 100% accurate.