Marshak, R.S., 1981, The variability of 'Mesozoic sedimentary rocks' in northern Yuma [and La Paz] County, western Arizona [abs.], in Howard, K.A., Carr, M.D., and Miller, D.M., eds., Tectonic framework of the Mohave and Sonoran Deserts, California and Arizona: U.S. Geological Survey Open-File Report 81-0503, p. 61-62.