@ARTICLE{apii94,
    AUTHOR = "C. Andr\'e and D. Gaff\'e",
    TITLE = "Ev\'enements et Conditions en {\sc Grafcet}",
    JOURNAL = "A.P.I.I.",
    YEAR = {1994},
    VOLUME = {28},
    NUMBER = {4},
    PAGES = {331--352}
}