HLAVÁČ, Jaroslav Čáp and
Michal HORSÁK. Nový výskyt plzáka Arion intermedius Normand, 1852 (Pulmonata: Arionidae) v CHKO Šumava (Západní Čechy) (The slug Arion intermedius Normand, 1852 (Pulmonata: Arionidae) - new find in the Šumava Protected Landscape Area (Western Bohemia)). In
Silva Gabreta. 5th ed. Vimperk, 2000, p. 113-120.