APA (7th ed.) Citation

Landis, P. H. (1948). Population problems: A cultural interpretation. American Book Company.

Chicago Style (17th ed.) Citation

Landis, Paul Henry. Population Problems: A Cultural Interpretation. New York: American Book Company, 1948.

MLA (9th ed.) Citation

Landis, Paul Henry. Population Problems: A Cultural Interpretation. American Book Company, 1948.