	Authors	Year	Title
	House	1978	Devonian amonoids from the Appalachians and their bearing on international zonation and corelation. Special Papers Paleontology, 21: 1-70, fig.1-12, pl.1-10; London.
	Roemer	1850	Beiträge zur geologischen Kenntniss des nordwestlichen Harzgebirges. Palaeontographica, 3: 1-67, pl.1-10; Cassel.