PT Unknown AU Roa-Valverde, AJ Thalhammer, A Toma, I Sicilia, M TI Towards a formal model for sharing and reusing ranking computations SE Proceedings of the 6th International Workshop on Ranking in Databases (DBRank 2012) held in conjunction with the 38th Conference on Very Large Databases (VLDB 2012), 27.08.2012, Instabul, Turkey PY 2012 LA english ER