Arendorf T M, van der Ross R
Dep. of Oral Medicine and Periodontology, WHO Collaborating Centre for Oral Health, Faculty of Dentistry, University of the Western Cape, Cape Town, South Africa.
Community Dent Oral Epidemiol. 1996 Aug;24(4):296-7. doi: 10.1111/j.1600-0528.1996.tb00863.x.