1. Aronson E Blaney N Stephan C Sikes J Snapp M (1978)The Jigsaw Classroom(Beverly Hills, CA: Sage)
2. Ball DL (1989) Beginnings [classroom transcript, 11, 12, and 18 September] ‘Mathematics and Teaching Through Hypermedia’ Project, College of Education, Michigan State University, East Lansing, MI, USA
3. With an Eye on the Mathematical Horizon: Dilemmas of Teaching Elementary School Mathematics