	Authors	Year	Title
	Foord & Crick	1897	Catalogue of the fossil Cephalopoda in the British Museum (Natural History). Part III, containing the Bactritidae and part of the Suborder Ammonoidea). pp.I-XXXIII, 1-303, 145 figs., London.
	Roemer	1850	Beiträge zur geologischen Kenntniss des nordwestlichen Harzgebirges. Palaeontographica, 3: 1-67, pl.1-10; Cassel.