	Authors	Year	Title
	Bisat	1924	The Carboniferous goniatites of the North of England and their zones. Proceedings of the Yorkshire Geological Society, 20: 40-124, pl.1-10; Leeds.
	Titus & Manger	2001	Mid-Carboniferous ammonoid biostratigraphy, Southern Nye County, Nevada: Implications of the first North American Homoceras. Journal of Paleontology, 75 (4, Supplement, Memoir 55): 1-31, 24 figs., Lawrence, KS.