APA (7th ed.) Citation

Hart, M. D., & Smith, W. W. (1925). The principles of sound signalling. D. Van Nostrand.

Chicago Style (17th ed.) Citation

Hart, Morris Daniel, and W. Whately Smith. The Principles of Sound Signalling. New York: D. Van Nostrand, 1925.

MLA (8th ed.) Citation

Hart, Morris Daniel, and W. Whately Smith. The Principles of Sound Signalling. D. Van Nostrand, 1925.