by the North American Geologic Map Committee, Edwin N. Goddard ... [et al.] ; compilation assistance by Derwin C. Bell ; prepared by collaboration of the Geological Society of America ... [et al.]U.S. Geological Survey1965
compiled by the United States Geological Survey in cooperation with the Geological Survey of Canada and Instituto Geologico de Mexico ; under the supervision of Bailey Willis and George W. Stose ; geologic drafting by Henry S. SeldenU.S. Geological Survey1911