K. Groth. Interaction and Presentation Laboratory (IPLab) Numerical Analysis
and Computing Science (Nada) Royal Institure of Technology (KTH), Stockholm, Sweden, (2004)
K. Groth, O. Frykholm, and A. Yngling. Proceedings of the ACM 2011 conference on Computer supported cooperative work, page 633--636. New York, NY, USA, ACM, (2011)