1. Translucency of Dental Porcelains
2. The Optical Properties of Diffusing Materials
3. Gettleman, L.; Herzberg, T.W.; Webber, R.L.; and Mof-Fa, J.: The Effect of Metal Surface Treatment on Masking Power of Opaque Porcelain. In: Dental Porcelain: The State of the Art-1977, Yamada, H.N., Ed. Los Angeles: Univ. of Southern Calif., 1977, p. 317.
4. Jelenko, J.F.: Crown and Bridge Construction, 5th ed. New Rochelle: J.F. Jelenko Co., 1968, p. 123.
5. Johnston, J.F.; Phillips, R.W.; and Dykema, R.W.: Modern Practice in Crown and Bridge Prosthodontics, 3rd ed. Philadelphia : W.B. Saunders Co., 1971, p. 420.