Gulinck, M. & Legrand, R., 1970. Notice explicative de la carte hydrogéologique au 50.000e du Tournaisis (Nappe du Calcaire Carbonifère). Memoirs of the Geological Survey of Belgium, 12, 11 p.
The printed version of the Memoirs Vol. 12 is available for sale at the GSB. For ordering, please contact gsb@naturalsciences.be
