Authors	Year	Title
Bisat	1940	An early Gastrioceras (G. braneroides sp. nov.) from North Wales. Transactions of the Leeds Geologists Association, 5: 330-335, fig.1-3; Kendal.
Korn	1997	The Palaeozoic ammonoids of the South Portuguese Zone. Memórias do Instituto geológico e Mineiro 33: 1-131, 69 text-figs., 16 pls., Lisboa.
Ramsbottom & Calver	1962	Some marine horizons containing Gastrioceras in North West Europe. Quatrième Congrès International de Stratigraphie et de Géologie du Carbonifère, Heerlen 1958, Compte Rendu 3: 571-576, 2 figs., pl.14, 15, Heerlen.