TY  - GEN
AU  - Petrich,Mario
TI  - Rings and semigroups
T2  - Lecture notes in mathematics
SN  - 0387067302 (New York)
U1  - 510/.8 s512/.4 
PY  - 1974///
CY  - Berlin, New York
PB  - Springer-Verlag
KW  - Semigroups
KW  - Associative rings
N1  - Cuprinde bibliografie si index
ER  -