The younger Precambrian fossils of the Grand Canyon, in Breed, W.J., and Roat, E.C., eds., Geology of the Grand Canyon

Ford, T.D., and Breed, W.J., 1974, The younger Precambrian fossils of the Grand Canyon, in Breed, W.J., and Roat, E.C., eds., Geology of the Grand Canyon: Flagstaff, Museum of Northern Arizona, and Grand Canyon Natural History Association, p. 34-40.