	Authors	Year	Title
	Paul	1939	Die Etroeungt-Schichten des Bergischen Landes. Jahrbuch der Preußischen Geologischen Landesanstalt, 59 (for 1938): 647-726, fig.1-4, pl.39-42; Berlin.
	Price	1982	Some Famennian (Upper Devonian) ammonoids from north western Europe. [unpublished dissertation, Hull]. Unpubl.Ph.D. Thesis,I-XXV,1-460,fig.1.1-1.7,fig.3.1-3.3,fig.4.1-4.16, fig.5.1-5.35, fig.6.1, fig.7.1-7.21, fig.8.1-8.2, pl.5.1-5.42, pl.7.1-7.6; Hull.
	Price & Korn	1989	Stratigraphically important Clymeniids (Ammonoidea) from the Famennian (Later Devonian) of the Rhenish Massif, West Germany. Courier Forschungsinstitut Senckenberg, 110: 257-294, fig.1-12; Frankfurt a.M.