Authors Year Title
Manger, Meeks & Stephen 1999 Pathologic Gigantism in Middle Carboniferous Cephalopods, Southern Midcontinent, United States.
In: Olóriz,F. & Rodríguez-Tovar,F.J.[eds.], Advancing Research on Living and Fossil Cephalopods, 77-89, 5 figs., New York.
Nassichuk, Furnish & Glenister 1965 The Permian ammonoids from Arctic Canada.
Bulletin of the Geological Survey of Canada, 131: 1-56, fig.1-17, tab.1-7, pl.1-5; Ottawa.