1. 1. W Malone, and D Koth : Tylman's Theory and Practice of Fixed Prosthodontics (ed 8 ). St Louis, MO, Ishiyaku Euro America, 1989 , pp285 -287 .
2. 2. J Pameijer : Periodontal and Occlusal Factors in Crown and Bridge Procedures . Amsterdam, Holland, Dental Center for Postgraduate Studies, 1985 , p353 .
3. 4. H Shillingburg, S Hobo, and L Whitsett : Fundamentals of Fixed Prosthodontics (ed 2 ). Chicago, IL, Quintessence, 1981 , pp241 -256 .
4. 5. S Rosenstiel, M Land, and J Fukimoto : Contemporary Fixed Prosthodontics (ed 1 ). St Louis, MO, Mosby, 1988 , p275 .