@inproceedings{AK11,
    author      =   "S. Almagor and O. Kupferman",
    title       =   "Max and sum semantics for alternating weighted automata", 
    booktitle   =   atva11,
    series      =   lncs,
    volume      =   "?",
    pages       =   "?",
    publisher   =   springer,
    year        =   2011
}