TY  - JOUR
AU  - Edward J. Tully
TI  - Expletives in languages and middle units in semigroups.
JO  - Semigroup forum
PY  - 1989
SP  - 77
EP  - 84
VL  - 38
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SF_1989__38_2_134942/
ID  - SF_1989__38_2_134942
ER  -