1. Yap, K.-H., & Wu, K. 2005. A soft relevance framework in content-based image retrieval systems. IEEE Transactions on Circuits and Systems, 15(2), 1557--1568.
2. J.Huang, S.R. Kunar, M.Mitra, W.J. Zhu, and R.Zabih. 1997. Image indexing using color correlogram, in Proc. IEEE Comp. Soc. Conf. Comp. Vis. And Patt. Recog., 762--768.
3. M.Stricker and M. Orengo. 1995. Similarity of color images, in Storage and Retrieval for Image and Video Databases, Proc. SPIE 2420, 381--392.
4. A.Pentland, R.Picard, and S. Sclaroff. 1994. Photobook: Content-based manipulation of image databases, SPIE Storage and Retrieval for Image and Video Databases II, no. 2185, 34--47.
5. Chiou-Shaan Fuh, Shun-Wen Cho, and Kai Essig. 2000. Hierarchical color image region segmentation for content-based image retrieval system, IEEE Transactions on Image Processing, vol. 9, no. 1.