Citation: J. Godefroid et S. Helsen, THE LAST FRASNIAN ATRYPIDA (BRACHIOPODA) IN SOUTHERN BELGIUM, Acta Palaeontologica Polonica, 43(2), 1998, pp. 241-272
Citation: S. Helsen, THE INFLUENCE OF HOST-ROCK COMPOSITION ON THE COLOR ALTERATION OF NAMURIAN CONODONTS FROM BELGIUM, Geologie en mijnbouw, 75(4), 1996, pp. 373-378
Citation: S. Helsen, BURIAL HISTORY OF PALEOZOIC STRATA IN BELGIUM AS REVEALED BY CONODONTCOLOR ALTERATION DATA AND THICKNESS DISTRIBUTIONS, Geologische Rundschau, 84(4), 1995, pp. 738-747
Citation: S. Helsen et P. Konigshof, CONODONT THERMAL ALTERATION PATTERNS IN PALEOZOIC ROCKS FROM BELGIUM,NORTHERN FRANCE AND WESTERN GERMANY, Geological Magazine, 131(3), 1994, pp. 369-386