TY  - JOUR
AU  - Havel, Václav
TI  - Free extensions of $(a,b)$-systems
JO  - Czechoslovak Mathematical Journal
PY  - 1970
SP  - 353
EP  - 356
VL  - 20
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1970.100972/
DO  - 10.21136/CMJ.1970.100972
LA  - en
ID  - 10_21136_CMJ_1970_100972
ER  -