Reference

Ted von Proschwitz, Karen Anna Okland, Pia Baagoe, Lauri Koli, Jan Okland, I. Valovirta (1995): A Further Supranational E.I.S.-Project in N. Europe: Mapping the Distribution of Large Freshwater Mussels (Margaritiferidae, Unionidae, Dreissenidae). – Mitteilungen der Deutschen Malakozoologischen Gesellschaft – 56-57: 51 - 52.