TY  - BOOK
AU  - Gradshtein,I.S., x
AU  - x
TI  - Direct and conerse theorems; the elements of symbolic logic: x
SN  - x
U1  - 510/GRD 
PY  - 1963///
CY  - Oxford
PB  - Pertgamon Press
KW  - Mathematics
N1  - x
ER  -