Multiset Processing Mathematical, Computer Science, and Molecular Computing Points of View - Calude, Christian S.; Calude, Christian S.; Paun, Gheorghe; Paun, Gheorghe; Rozenberg, Grzegorz; Rozenberg, Grzegorz; Salomaa, Arto; Salomaa, Arto (Springer Berlin Heidelberg : Imprint: Springer, 2001)