[1]
E. B. A. Bisdom, A. Gerlofsma, J. N. B. Poelman, and P. A. Riezebos, “Composite grains in heavy-mineral concentrates and their significance in the differentiation of surface deposits at the confluence of the Maas (Meuse) and Roer (Rur) rivers.”, njg, pp. 407-416, Jan. 1978.