TY  - JOUR
AU  - Solomon Feferman
TI  - Two notes on abstract model theory. II. Languages for which, the set of valid sentences is semi-invariantly implicitly definable
JO  - Fundamenta Mathematicae
PY  - 1975
SP  - 111
EP  - 130
VL  - 89
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/fm-89-2-111-130/
DO  - 10.4064/fm-89-2-111-130
LA  - en
ID  - 10_4064_fm_89_2_111_130
ER  -