	Authors	Year	Title
	Horn, Kullmann & Oliveira	1989	New goniatite horizons at the Visean/Namurian boundary in Southwest Portugal. Bulletin de la Societé belge de Géologie, 98-3/4: 475-481, fig.1-4, pl.1; Bruxelles
	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.