Charles D. Walcott, America's pioneer in Precambrian paleontology and stratigraphy, in Kupsch, W. O., and Sarjeant, W. A. S., eds., History of concepts in Precambrian geology

Yochelson, E.L., 1979, Charles D. Walcott, America's pioneer in Precambrian paleontology and stratigraphy, in Kupsch, W. O., and Sarjeant, W. A. S., eds., History of concepts in Precambrian geology: Geological Association of Canada Special Paper 19, p. 261-292.