Abdullah, N. H. L. (2005). The Effectiveness of using dynamic geometry software on students’ achievement in geometry. Unpublished Master’s Thesis, Kuala Lumpur, Malaysia: University Malaya.
 Bennett, D. (1999). Exploring geometry with The Geometer’s Sketchpad. Emeryville, CA: Key Curriculum Press.
 Choi, S. S. (1996). Students’ learning of geometry using computer software as a tool: Three case studies. Ph.D. Dissertation, Georgia: University of Georgia.
 Choi-Koh, S. S. (1999). A student’s learning of geometry using the computer. Journal of Educational Research, 92, 301-311.
 Chi-Koh, & Sang Sook (2000). The activities based on van Hiele model using computer as a tool. Journal of the Korean Society of Mathematical Education Series D: Research in Mathematical Education, 4, 63-77.
 Driskell, S. O. S. (2004). Fourth-grade students’ reasoning about properties of two-dimensional shapes. Ph.D. Dissertation, Virginia: University of Virginia.
 Elchuck, L. M. (1992). The effects of software type, mathematics achievement, spatial visualization, locus of control, independent time of investigation, and van Hiele level on geometric conjecturing ability. Ph.D Dissertation, University Park, PA: The Pennsylvania State University, URL (last checked on 10 April 2004)
 Lim, C. S., & Fatimah Saleh (2010). What can we learn? In C. S. Lim & L. K. Kor (Eds.), Innovative use of Geometer’s Sketchpad (GSP) through lesson study collaboration (pp. 51-62). Penang: Basic Educational Research Unit, School of Educational Studies, Universiti Sains Malaysia.
 Fernandez, C., & Yoshida, M. (2004). Lesson Study: A Japanese Approach to Improving Mathematics Teaching and Learning. Mahwah, New Jersey: Lawrence Erlbaum Associates.
 Finzer, W., & Jackiw, N. (1998). Dynamic manipulation of mathematical objects. URL (last checked on 2 February 2004)
 Frerking, B. G. (1995). Conjecturing and proof-writing in dynamic geometry. Ph.D. Dissertation, Atlanta, Georgia: Georgia State University, URL (last checked on 10 April 2004)
 Goh, S. I. (2010). The significance of motivator in a lesson study group. In C. S. Lim & L. K. Kor (Eds.), Innovative use of Geometer’s Sketchpad (GSP) through lesson study collaboration (pp. 51-62). Penang: Basic Educational Research Unit, School of Educational Studies, Universiti Sains Malaysia.
 Hannafin, R. D., Burruss, J. D., & Little, C. (2001). Learning with dynamic geometry programs: Perspectives of teachers and learners. The Journal of Educational Research, 94, 132-144.
 Isoda, M., Stephens, M., Ohara, Y., & Miyakawa, T. (2007). Japanese Lesson Study in Mathematics: Its Impact, Diversity and Potential for Educational Improvement. New Jersey: World Scientific.
 July, R. A. (2001). Thinking in three dimensions: Exploring students’ geometric thinking and spatial ability with The Geometer’s Sketchpad. Ed.D. Dissertation, Miama, Floria: Florida International University.
 Kalsom Saidin. (2010). Two in one lesson: “Geolessdy”. In C. S. Lim & L. K. Kor (Eds.), Innovative use of Geometer’s Sketchpad (GSP) through lesson study collaboration (pp. 32-40). Penang: Basic Educational Research Unit, School of Educational Studies, Universiti Sains Malaysia.
 Kasmawati Che Osman (2006). Meninjau penggunaan Geometer Sketch Pad (GSP) di kalangan guru matematik sekolah menengah Pulau Pinang. Unpublished M.Ed thesis, Universiti Sains Malaysia, Penang.
 Lewis, C. (2000). Lesson Study: The core of Japanese professional development. Paper presented at the American Educational Research Association meeting, April 2000.
 Lewis, C., & Tsuchida, I. (1998). A lesson is like a swiftly flowing river: Research lessons and the improvement of Japanese education. American Educator, 14-17 & 50-52.
 McClintock, E., Jiang, Z., & July, R. (2002). Students’ development of three-dimensional visualization in the Geometer’s Sketchpad Environment. Proceedings of the Annual Meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education (ERIC Document Reproduction Service No. ED 471 759)
 Olive, J. (2000). Learning geometry intuitively with the aid of a new computer tool: The Geometer’s Sketchpad. The Mathematics Educator, 2, 1-5. URL (last checked on 11 August 2003)
 Shimahara, N. K. (1998). The Japanese model of professional development: Teaching as craft. Teaching & Teacher Education, 14, 451- 462. doi:10.1016/S0742-051X(97)00055-3
 Stigler, J. W., & Hiebert, J. (1997). Understanding and improving classroom mathematics instruction: An overview of the TIMSS video study. Phi Delta Kappan, 79, 14-21.
 Stigler, J. W., & Hiebert, J. (1999). The Teaching Gap: Best Ideas from the World’s Teachers for Improving Education in the Classroom. NewYork: The Free Press.
 Tan, K. A. (2010). In search of best practices. In C. S. Lim & L. K. Kor (Eds.), Innovative use of Geometer’s Sketchpad (GSP) through lesson study collaboration (pp. 41-50). Penang: Basic Educational Research Unit, School of Educational Studies, Universiti Sains Malaysia.
 Teoh, B. T., & Fong, S. F. (2005). The Effects of Geometer’s Sketchpad and Graphic Calculator in the Malaysian Mathematics Classroom. Malaysian Online Journal of Instructional Technology, 2, 82-96.
 Thompson, E. (2006). Euclid, the van Hiele levels, and the Geometer’s Sketchpad. (MST thesis, Florita Atlantic University, 2006). Masters Abstracts International, 44, 2529. URL (last checked on 2 February 2007) http://wwwlib.umi.com/ dissertations/fullcit/1435803
 Yoshida, M. (1999). Lesson Study (Jugyokenkyu) in elementary school mathematics in Japan: A case study. Paper presented at the American Educational Research Association (1999 Annual Meeting), Montreal, Canada.