1. Kirschbaum B. Atlas of Chinese tongue diagnosis. Seattle: Eastland Press; 2000:6–10.
2. Tao LM, Xu GH. Color problem and application in computer vision. Chin Sci Bull (Chin) 2001;46:178–190.
3. Wu ZZ, Li M, Zhang SW, Cai Y, Zhang YF, Chen MY. Study on the molecular mechanism of lingual epithelial cell apoptosis and its related genes in different tongue furs. Chin J Integr Tradit West Med (Chin) 2005;25:986–988.
4. Wu ZZ, Li M, Zhang YF, Chen MY. Study on relationship between the thickness of tongue fur and the expressions of apoptosis-related genes of the tongue epithelial cells in patients with diseases of the digestive system. J Tradit Chin Med (Chin) 2007;27:148–152.
5. Chiu CC. The development of a computerized tongue diagnosis system. Biomed Eng Appl Basis Commun 1996;8:342–350.