Two-way latent grouping model for user preference prediction
Eerika Savia, Kai Puolamäki, Janne Sinkkonen and Samuel Kaski
In: UAI 2005, 26-29 July 2005, Edinburgh, Scotland.
A pre-relational databases datamodel. "Preceeded" by the relational model since the flexibility of this makes it hard to work with. Now re-invented in RDF :)
J. Hausmann, and S. Kent. SoftVis '03: Proceedings of the 2003 ACM symposium on Software visualization, page 169--178. New York, NY, USA, ACM Press, (2003)