	Authors	Year	Title
	Müller	1956	Cephalopodenfauna und Stratigraphie des Oberdevons von Schleiz und Zeulenroda in Thüringen. Beih. Geologisches Jahrbuch, 20: 1-93, fig.1-15, 1 tab., pl.1,2; Hannover.
	Selwood	1960	Ammonoids and Trilobites from the Upper Devonian and lowest Carboniferous of the Launceston area of Cornwall. Palaeontology, 3 (2): 153-185, fig.1-8, pl.26-29; London.