Washington Water Power Company & Washington Water Power Company. Information and Special Activities Department. (1979). History of the Washington Water Power Company. Washington Water Power Company, Information and Special Activities Dept..
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)Washington Water Power Company và Washington Water Power Company. Information and Special Activities Department. History of the Washington Water Power Company. [Spokane, Wash.]: Washington Water Power Company, Information and Special Activities Dept., 1979.
Trích dẫn kiểu MLA (xuất bản lần thứ 8)Washington Water Power Company và Washington Water Power Company. Information and Special Activities Department. History of the Washington Water Power Company. Washington Water Power Company, Information and Special Activities Dept., 1979.