(1)
P. Buurman; A.G. Jongmans; C. Kasse; B. van Lagen. Discussion: Oil Seepage or Fossil Podzol? An Early Oligocene Oil Seepage at the Southern Rim of the North Sea Basin, Near Leuven (Belgium) by E.D. Van Riessen & N. Vandenberghe, Geologie En Mijnbouw 74: 301-312 (1996). njg 1998, 77, 93-98.