TY  - JOUR
AU  - Ivánek, Jiří
TI  - The non-axiomatizability of the observational predicate calculus (generalized Trachtenbrot's theorems)
JO  - Commentationes Mathematicae Universitatis Carolinae
PY  - 1977
SP  - 41
EP  - 57
VL  - 18
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMUC_1977__18_1_a3/
LA  - en
ID  - CMUC_1977__18_1_a3
ER  -