Geological Survey (U.S.) & Drewes, H. (1991). Geologic map of the Swisshelm Mountains, and a description of the development of the Swisshelm and Pedregosa Mountains, Cochise County, Arizona. The Survey.
Chicago Style (17th ed.) CitationGeological Survey (U.S.) and Harald Drewes. Geologic Map of the Swisshelm Mountains, and a Description of the Development of the Swisshelm and Pedregosa Mountains, Cochise County, Arizona. Reston, Va.: The Survey, 1991.
MLA (9th ed.) CitationGeological Survey (U.S.) and Harald Drewes. Geologic Map of the Swisshelm Mountains, and a Description of the Development of the Swisshelm and Pedregosa Mountains, Cochise County, Arizona. The Survey, 1991.
Warning: These citations may not always be 100% accurate.