APA (7th ed.) Citation

Butts, T. (1928). German air compressors. [publisher not identified].

Chicago Style (17th ed.) Citation

Butts, Thomas. German Air Compressors. Washington, D.C.: [publisher not identified], 1928.

MLA (9th ed.) Citation

Butts, Thomas. German Air Compressors. [publisher not identified], 1928.