Cita APA (7th ed.)

Langsdorf, A. S. (1940). Principles of direct-current machines (5th ed.). McGraw-Hill book company, inc..

Cita Chicago (17th ed.)

Langsdorf, Alexander Suss. Principles of Direct-current Machines. 5th ed. New York and London: McGraw-Hill book company, inc., 1940.

Cita MLA (8th ed.)

Langsdorf, Alexander Suss. Principles of Direct-current Machines. 5th ed. McGraw-Hill book company, inc., 1940.