1. Current status of shade selection and color matching;Preston;Quintessence Int,1985
2. Organizing color in dentistry;Miller;J Am Dent Assoc,1987
3. Coverage errors of two shade guides;O'Brien;Int J Prosthodont,1991
4. Color comparison of two shade guides;Paravina;Int J Prosthodont,2002
5. Advances in color matching;Brewer;Dent Clin North Am,2004