TY  - JOUR
AU  - Niederle, Josef
TI  - Transitivity of principal tolerances is not a Mal'cev property
JO  - Czechoslovak Mathematical Journal
PY  - 1990
SP  - 563
EP  - 565
VL  - 40
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1990.102410/
DO  - 10.21136/CMJ.1990.102410
LA  - en
ID  - 10_21136_CMJ_1990_102410
ER  -