webpage http://www.scopus.com/inward/record.url?eid=2-s2.0-33845983539&partnerID=MN8TOARS http://dx.doi.org/10.1145/1166253.1166305
published in Proceedings of the 19th annual ACM symposium on User interface software and technology Journal Proceedings of the 19th annual ACM symposium on User interface software and technology Proceedings UIST: Proceedings of the Annual ACM Symposium on User Interface Softaware and Technology Proceedings