M. Klawe, und E. Phillips. CSCL '95: The first international conference on Computer support for collaborative learning, Seite 209--213. Mahwah, NJ, USA, Lawrence Erlbaum Associates, Inc., (1995)
D. Carraher, und D. Earnest. Proceedings of the 2003 Joint Meeting of PME and PMNA (PME27 and PME-NA25), 2, Seite 173--180. 1776 University Av., Honolulu, HI 96822, International Group for the Psychology of Mathematics Education, College of Education, University of Hawai'i, (Juli 2003)
R. Goldstein, und D. Pratt. Proceedings of the 25th Conference of the International Group for the Psychology of Mathematics Education (PME25), 3, Seite 49--56. PO Box 9432, 3506 GK Utrecht, The Netherlands, Freudenthal Institute, Faculty of Mathematics and Computer Science, Uthrect University, (Juli 2001)