1. Fundamentals of fixed prosthodontics;Shillingburg,1981
2. Modern practice in crown and bridge prosthodontics;Johnston,1971
3. The convergence angle in teeth prepared for artificial crowns;Ohm;J Oral Rehabil,1978
4. Taper of clinical crowns;Weir;J Dent Res,1985
5. Taper and length of crown preparations by general practice residents;Nordlander;J Dent Res,1985