APA (7th ed.) Citation

McDougal, W. L., Keith, F. E., & Ranson, R. R. (1947). Direct current motors and generators: Principles, operation, and maintenance. [publisher not identified].

Chicago Style (17th ed.) Citation

McDougal, Wynne Luther, Fay Ellsworth Keith, and Richard Rose Ranson. Direct Current Motors and Generators: Principles, Operation, and Maintenance. Chicago: [publisher not identified], 1947.

MLA (9th ed.) Citation

McDougal, Wynne Luther, et al. Direct Current Motors and Generators: Principles, Operation, and Maintenance. [publisher not identified], 1947.