G. Conole, P. McAndrew, and Y. Dimitriadis. Techniques for Fostering Collaboration in Online Learning Communities: Theoretical and Practical Perspectives, Hershey, New York, (2010)
A. Dearden, J. Finlay, E. Allgar, and B. Mcmanus. People and Computers XVII: Memorable yet Invisible, Proceedings of HCI'2002, page 159-174. Springer Verlag, (2002)