1. Abouzied, A., Hellerstein, J.M., Silberschatz, A.: Playful query specification with DataPlay. Proc. VLDB Endow. 5(12), 1938–1941 (2012)
2. Benford, S., Fahlén, L.E.: Awareness, focus, and aura: A spatial model of interaction in virtual worlds. In: Salvendy, G., Smith, M.J. (eds.) HCI (2), pp. 693–698. Elsevier (1993)
3. Catarci, T., Costabile, M.F., Levialdi, S., Batini, C.: Visual query systems for databases: A survey. Journal of Visual Languages and Computing 8(2), 215–260 (1997)
4. Chaudhuri, S., Dayal, U.: An overview of data warehousing and OLAP technology. SIGMOD Rec. 26(1), 65–74 (1997)
5. CIDR 2013, Sixth Biennial Conference on Innovative Data Systems Research, Asilomar, CA, USA, January 6-9 (2013), Online Proceedings,
http://www.cidrdb.org