APA (7th ed.) Citation

Merrill, W. S. (1939). Code for classifiers: Principles governing the consistent placing of books in a system of classification. American Library Association.

Chicago Style (17th ed.) Citation

Merrill, William Stetson. Code for Classifiers: Principles Governing the Consistent Placing of Books in a System of Classification. Chicago: American Library Association, 1939.

MLA (9th ed.) Citation

Merrill, William Stetson. Code for Classifiers: Principles Governing the Consistent Placing of Books in a System of Classification. American Library Association, 1939.