K. Gajos, M. Czerwinski, D. Tan, and D. Weld. Proceedings of the Working Conference on Advanced Visual Interfaces, page 201--208. New York, NY, USA, ACM, (2006)
W. Stuerzlinger, O. Chapuis, D. Phillips, and N. Roussel. Proceedings of the 19th annual ACM symposium on User interface software and technology, page 309--318. New York, NY, USA, ACM, (2006)