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 :)
M. Becker, J. Mueller, A. Hotho, und G. Stumme. 1st International Workshop on Pervasive Urban Crowdsensing Architecture and Applications, PUCAA 2013, Zurich, Switzerland -- September 9, 2013. Proceedings, Seite New York, NY, USA. ACM, (2013)Accepted for publication.
R. Akbarinia, und F. Masseglia. Machine Learning and Knowledge Discovery in Databases, Volume 8188 von Lecture Notes in Computer Science, Springer Berlin Heidelberg, (2013)