United States. War Department. (1921). Duluth-Superior Harbor: Statistical report of marine commerce of Duluth, Minn., and Superior, Wis. for calendar year 1921; with supplementary report of commerce of Keweenaw Waterway, Mich. GPO.
Chicago Style (17th ed.) CitationUnited States. War Department. Duluth-Superior Harbor: Statistical Report of Marine Commerce of Duluth, Minn., and Superior, Wis. for Calendar Year 1921; with Supplementary Report of Commerce of Keweenaw Waterway, Mich. [Washington]: GPO, 1921.
MLA (9th ed.) CitationUnited States. War Department. Duluth-Superior Harbor: Statistical Report of Marine Commerce of Duluth, Minn., and Superior, Wis. for Calendar Year 1921; with Supplementary Report of Commerce of Keweenaw Waterway, Mich. GPO, 1921.
Warning: These citations may not always be 100% accurate.