TY  - BOOK
AU  - Jeffrey, Richard.
TI  - Formal logic: ITs scope and limits / 
SN  - 0 -07-032321-6
U1  - R1 
PY  - 1970///
CY  - New YOrk : 
PB  - McGraw-Hill Book Company , 
KW  - Philosophy<Soundness>
ER  -