TY  - BOOK
AU  - Kuich Werner
AU  -  Salomaa Arta
TI  - Semirings, automata languages
T2  - EATSC monographs on theoretical computers science; 5
U1  - B:(R1), M6 
PY  - 1986///
CY  - Berlin
PB  - Springer-Verlag         
KW  - Mathematical logic
ER  -