Lee, Ickjai, Qu, Yang, and Lee, Kyungmi (2012) Mining qualitative patterns in spatial cluster analysis. Expert Systems with Applications, 39 (2). pp. 1753-1762.

Qu, Yang, Lee, Kyungmi, and Lee, Ickjai (2011) Cluster polygonization and qualitative cluster reasoning: overview. International Journal of Advancements in Computing Technology, 3 (3). pp. 1-9.

Qu, Yang, Lee, Kyungmi, and Lee, Ickjai (2010) Making sense of clusters through qualitative spatial reasoning. In: Proceedings of 6th International Conference on Advanced Information Management and Service. pp. 67-72. From: IMS 2010 6th International Conference on Advanced Information Management and Service, 30 November - 2 December 2010, Seoul, Korea.

Qu, Yang, Lee, Kyungmi, and Lee, Ickjai (2009) Qualitative cluster reasoning framework for decision making. In: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC. pp. 1321-1326. From: 2009 Fifth International Joint Conference on INC, IMS and IDC, 25-27 August 2009, Seoul, Korea.