Sterki, V. 1906. New species of Pisidium. Nautilus 20(2): 17-20. Available electronically.
Sterki, 1906. Nautilus 20(2): ??.
Sterki, 1906. Nautilus 20(2): ??.
Sterki, 1906. Nautilus 20(2): ??.
Sterki, 1906. Nautilus 20(2): ??.
Sterki, 1906. Nautilus 20(2): ??.