APA (7th ed.) Citation

Waddell, C. W. (1918). An introduction to child psychology. Houghton-Mifflin company.

Chicago Style (17th ed.) Citation

Waddell, Charles Wilkin. An Introduction to Child Psychology. Boston, New York [etc.]: Houghton-Mifflin company, 1918.

MLA (9th ed.) Citation

Waddell, Charles Wilkin. An Introduction to Child Psychology. Houghton-Mifflin company, 1918.