Original Ordovician stratigraphy discussed in Goebel, E.D., 1968, Ordovician System, in, Zeller, D.E., (ed.); The stratigraphic succession in Kansas: Kansas Geological Survey, Bulletin, no. 189, pp. 14-15 http://www.kgs.ku.edu/Publications/Bulletins/189/05_ordo.html
Original Cambrian stratigraphy discussed in Goebel, E.D., 1968, Cambrian System, in, Zeller, D.E., (ed.); The stratigraphic succession in Kansas: Kansas Geological Survey, Bulletin, no. 189, pp. 11-13 http://www.kgs.ku.edu/Publications/Bulletins/189/04_paleoz.html#CAMB