Lois Wright Hawkes Sharon J. Derry Elke A. Rundensteiner Individualized Tutoring Using an Intelligent Fuzzy Temporal Relational Database. 409-429 1990 33 International Journal of Man-Machine Studies 4 db/journals/ijmms/ijmms33.html#HawkesDR90 http://dx.doi.org/10.1016/S0020-7373(05)80040-9