Authors Year Title
Boardman, Work & Mapes 1994 Biostratigraphy of Middle and Late Pennsylvanian (Desmoinesian-Virgilian) ammonoids. [Boardman,D.R., D.M.Work, Mapes,R.H. & Barrick,J.E.].
Kansas Geological Survey Bulletin 232, 121 p., 26 figs., 1 tabl., 5 pls., Lawrence, KS.