	Authors	Year	Title
	Foerste	1928	American Arctic and related Cephalopods. Bul. Denison Univ., J. Sci. Lab., 23: 1-110, pl.1-29;
	Miller	1938	Devonian ammonoids of America. Special Papers, Geological Society of America, 14: 1-262, fig.1-41, pl.1-39; Baltimore.