1. Swick, R.R., Ackerman, M.S.: The X Toolkit: More Bricks for Building User Interfaces, or Widgets for Hire. In: Proceedings of the Usenix Winter 1988 Conference, pp. 221–228 (1988)
2. Conner, B.D., Snibbe, S.S., Herndon, K.P., Robbins, D.C., Zeleznik, R.C., van Dam, A.: Three-dimensional widgets. In: I3D 1992: Proceedings of the 1992 Symposium on Interactive 3D Graphics, pp. 183–188. ACM, New York (1992)
3. Ryall, K., Esenther, A., Forlines, C., Shen, C., Shipman, S., Morris, M.R., Everitt, K., Vernier, F.: Identity-Differentiating Widgets for Multiuser Interactive Surfaces. IEEE Computer Graphics and Applications 26(5), 56–64 (2006)
4. Rohs, M.: Visual Code Widgets for Marker-Based Interaction. In: ICDCSW 2005: Proceedings of the Fifth International Workshop on Smart Appliances and Wearable Computing, pp. 506–513. IEEE Computer Society, Washington, DC (2005)
5. Dearman, D., Truong, K.N.: BlueTone: a framework for interacting with public displays using dual-tone multi-frequency through bluetooth. In: Ubicomp 2009: Proceedings of the 11th International Conference on Ubiquitous Computing, pp. 97–100. ACM, New York (2009)