- ICLS 1, page 3-24. International Society of the Learning Sciences, (2008)
- CSCW, page 65-84. (1988)
- CSCL, page 318-324. International Society of the Learning Sciences, (2002)
- CSCL, page 23. International Society of the Learning Sciences, (2002)
- Objects, contradictions and collaboration in medical cognition: an activity-theoretical perspective.Artificial Intelligence in Medicine 7(5):395-412 (1995)
- Computer Supported Cooperative Work 8(1-2):63-93 (1999)
- Computer Supported Cooperative Work 8(1-2):1-8 (1999)
- NordiCHI, page 863-866. ACM, (2010)
- IJMBL 1(2):1-18 (2009)
- (April 2005)http://www.zengestrom.com/blog/2005/04/why_some_social.html accessed 10-Oct-2008 .
- Orienta-Konsulit, Helsinki, (1987)
- Pergamon, (2003)
- Orienta-Konsultit Oy, Helsinki, (1987)
- Internationale Studien Tätigkeitstheorie BdWi, Marburg, (1999)
- Journal of Education and Work 14(1):133-156 (2001)
- International cultural-historical human sciences Lehmanns Media, Berlin, (2005)
- (April 2005)http://www.zengestrom.com/blog/2005/04/why_some_social.html accessed 10-Oct-2008 .
- Orienta-Konsultit Oy., Helsinki, (1987)
- Interacting with Computers 20(2):256-259 (2008)
- Orienta-Konsultit Oy., Helsinki, (1987)


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