@article {IOPORT.50065051,
    author       = {Klinkenberg, S. and Straatemeier, M. and Van Der Maas, H. L. J.},
    title        = {Computer adaptive practice of maths ability using a new item response model for on the fly ability and difficulty estimation},
    year         = {2011},
    journal      = {Computers & Education},
    volume       = {57},
    number       = {2},
    pages        = {1813-1824},
    doi          = {10.1016/j.compedu.2011.02.003},
    identifier   = {50065051},
}