APA (7th ed.) Citation

Frey, J. P. (1945). Craft unions of ancient and modern times. [publisher not identified].

Chicago Style (17th ed.) Citation

Frey, John P. Craft Unions of Ancient and Modern Times. [Washington, D.C.]: [publisher not identified], 1945.

MLA (9th ed.) Citation

Frey, John P. Craft Unions of Ancient and Modern Times. [publisher not identified], 1945.