R. W. Faas; S. Wartel. Mud Is Transported to the Dutch Delta Area from the Rhine, Waal, Maas and Scheldt Rivers (resp. 0,6; 2,5; 0,7 and 0,7 Million tons/Year). Above, in the Rotterdam Waterway about 3,5 Million Tons of Mud Per Year Are Brought in from the Sea. The Mud of the U. njg 1977, 211-218.