Willingham, W. F. (1983). Army engineers and the development of Oregon: A history of the Portland District, U.S. Army Corps of Engineers. U.S. Army Corps of Engineers.
Cita Chicago Style (17a ed.)Willingham, William F. Army Engineers and the Development of Oregon: A History of the Portland District, U.S. Army Corps of Engineers. [Washington, D.C.?: U.S. Army Corps of Engineers, 1983.
Cita MLA (8a ed.)Willingham, William F. Army Engineers and the Development of Oregon: A History of the Portland District, U.S. Army Corps of Engineers. U.S. Army Corps of Engineers, 1983.
Precaución: Estas citas no son 100% exactas.