1. Pontic-Residual Ridge Relationship: A Research Report;Stein;J. Prosthet. Dent.,1966
2. Modern Practice in Crown and Bridge Prosthodontics;Johnston,1965
3. Goldman, H. M., and Cohen, D. W.: Periodontal Therapy, ed. 4, St. Louis, The C. V. Mosby Company, chap. “Etiology.”
4. Roughness of Pontic Materials and Dental Plaque;Clayton;J. Prosthet. Dent.,1970