TY  - JOUR
AU  - Stefan Schwarz
TI  - A theorem on binary relations and infinite languages.
JO  - Semigroup forum
PY  - 1979
SP  - 307
EP  - 316
VL  - 17
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SF_1979__17_134325/
ID  - SF_1979__17_134325
ER  -