TY  - GEN
AU  - Goberstein, Simon M.
AU  - Higgins, Peter M.
AU  - 
TI  - SEMIGROUPS AND THEIR APPLICATIONS
U1  - 512.2 
PY  - 1987///
CY  - Dordrecht
PB  - Reidel
KW  - Semigroups -- Cong
ER  -