1. “Clustering by scale-space filtering”;Leung;IEEE Transactions on Pattern Analysis and Machine Intelligence,2000
2. “ Evaluation of text document clustering approach based on particle swarm optimization”;Karol;Central European Journal of Computer Science,2013
3. “On finding the number of clusters”;Kothari;Pattern Recognition Letters20,1999
4. Han, Kamber “Data Mining Concepts and Techniques.” Morgan KauffmanPublishers.
5. “ Self-organized formation of topologically correct feature maps. ”;Kohonen;Biol. Cybern43,1982