TY  - JOUR
AU  - Hartfiel, Darald J.
AU  - Maxson, Carlton J.
TI  - A matrix characterization of the maximal groups in $\beta_X$
JO  - Czechoslovak Mathematical Journal
PY  - 1975
SP  - 274
EP  - 278
VL  - 25
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1975.101317/
DO  - 10.21136/CMJ.1975.101317
LA  - en
ID  - 10_21136_CMJ_1975_101317
ER  -