@article{fersman07task,
    author = {Elena Fersman and Pavel Krcal and Paul Pettersson and Wang Yi},
    title = {Task Automata: Schedulability, Decidability and Undecidability},
    journal = {Information and Computation},
    volume = {205},
    number = {8},
    pages = {1149--1172},
    year = {2007}
}