APA (7th ed.) Citation

United States. Board of Engineers for Rivers and Harbors. (1940). The Port of Duluth-Superior, Minn. and Wis., Revised 1939. [s.n.].

Chicago Style (17th ed.) Citation

United States. Board of Engineers for Rivers and Harbors. The Port of Duluth-Superior, Minn. and Wis., Revised 1939. [Washington]: [s.n.], 1940.

MLA (9th ed.) Citation

United States. Board of Engineers for Rivers and Harbors. The Port of Duluth-Superior, Minn. and Wis., Revised 1939. [s.n.], 1940.