Authors: Bless, M. J. M. --- Boonen, P. --- Bouckaert, Jos --- Brauckmann, C. --- Conil, R. --- et al. Dusar, Michiel --- Felder, P. J. --- Felder, Werner M. --- Gökdag, H. --- Kockel, F. --- Laloux, M. --- Langguth, Horst Robert --- Meer Mohr, C.G. van der --- Meesen, J. P. M. Th. --- Op het Veld, F. --- Paproth, E. --- Pietzner, Horst --- Plum, J. --- Poty, Edouard --- Scherp A. --- Schulz, R. --- Streel, M. --- Thorez, Jacques --- Van Rooijen, P. --- Vanguestaine, M. --- Vieslet, J.L. --- Wiersma, D.J. --- Winkler prins, C.F. --- Wolf, Michaela.
Year: 1981 Publisher: Haarlem : Rijks Geologische Dienst