APA (7th ed.) Citation

Wallis, J. E., Jr. (1931). German machinery industry in 1930. [publisher not identified].

Chicago Style (17th ed.) Citation

Wallis, James E., Jr. German Machinery Industry in 1930. Washington, D.C.: [publisher not identified], 1931.

MLA (9th ed.) Citation

Wallis, James E., Jr. German Machinery Industry in 1930. [publisher not identified], 1931.