TY  - BOOK
T1  - Logic argument, refutation, and proof
A1  - Purtill, Richard L. 1931-
LA  - English
PP  - New York
PB  - Harper & Row
YR  - 1979
UL  - https://ds.mainlib.upd.edu.ph/Record/UP-1685523046125049566
OP  - 412
CN  - BC177 P87
SN  - 0063869004
KW  - Evidence.
KW  - Logic : Problems, exercises, etc.
KW  - Reasoning.
KW  - Refutation (Logic)
ER  -