APA (7th ed.) Citation

Engelhardt, N. L. (1941). ... Elementary school classrooms. Teachers college, Columbia university.

Chicago Style (17th ed.) Citation

Engelhardt, Nicholaus Louis. ... Elementary School Classrooms. New York: Teachers college, Columbia university, 1941.

MLA (9th ed.) Citation

Engelhardt, Nicholaus Louis. ... Elementary School Classrooms. Teachers college, Columbia university, 1941.