TY  - BOOK
AU  - Purtill,Richard L.
TI  - Logic: argument, refutation, and proof 
SN  - 0063869004
AV  - BC177 .P87
U1  - 160 
PY  - 1979///
CY  - New York
PB  - Harper & Row
KW  - Reasoning
KW  - Refutation (Logic)
KW  - Evidence
KW  - Logic
KW  - Problems, exercises, etc
N1  - Includes index; Bibliography: p. 408
ER  -