Drepanostoma helenae, a new helicodontine land snail from the Lower Pliocene of Balze di Caspreno near Siena (central Italy) and a discussion on the status of Protodrepanostoma Germain, 1929 (Gastropoda, Pulmonata: Hygromiidae)
Manganelli Giuseppe et Giusti Folco, Drepanostoma helenae, a new helicodontine land snail from the Lower Pliocene of Balze di Caspreno near Siena (central Italy) and a discussion on the status of Protodrepanostoma Germain, 1929 (Gastropoda, Pulmonata: Hygromiidae), Bollettino della Societa paleontologica italiana , 39(3), 2000, pp. 351-358