M. Golfarelli, S. Rizzi, and I. Cella. DOLAP '04: Proceedings of the 7th ACM international workshop on Data warehousing and OLAP, page 1--6. New York, NY, USA, ACM Press, (2004)
O. Marjanovic. HICSS '07: Proceedings of the 40th Annual Hawaii International Conference on System Sciences, page 215c. Washington, DC, USA, IEEE Computer Society, (2007)