The Mollusca of the estuarine region of the rivers Rhine, Meuse and Scheldt in relation to the hydrography of the area: 4. The genus Sphaerium
Wolff, W.J. (1970). The Mollusca of the estuarine region of the rivers Rhine, Meuse and Scheldt in relation to the hydrography of the area: 4. The genus Sphaerium. Basteria 34(3-4): 75-90