1. The fused porcelain crown;Adair;Revista Internazionale di Parodontologia e Odontoiatria Ricostruttiva,1984
2. A glass-ceramic synthesis to avoid dark and shadow zones on gingiva;Geller;Quintessenz der Zahntechnik,1987
3. The Optec H.P.S. system. Biocompatibility—fair to practice—natural;Suckart;Dental Labor,1987
4. The “Empress” technique. A new procedure for the manufacture of crowns, inlays, and veneers in porcelain;Wohlwend;La Quintessenza Odontotecnica,1991
5. The “Empress” system. A new possibility for the manufacture of crowns, inlays, and veneers;Wohlwend;Il Nuovo Laboratorio Odontotecnico,1991