Quirynen Marc, Gijbels Frieda, Jacobs Reinhilde
Department of Periodontology, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Catholic University Leuven, Belgium.
Periodontol 2000. 2003;33:129-44. doi: 10.1046/j.0906-6713.2002.03311.x.