Mariano, John, and Grauch, V.J.S., 1988, Aeromagnetic maps of the Colorado River region including the Kingman, Needles, Salton Sea, and El Centro 1o x 2o quadrangles, California, Arizona, and Nevada: U.S. Geological Survey Miscellaneous Field Studies Map MF-2023, 3 sheets, scale 1:250,000.
