TY  - BOOK
AU  - Churchill, Robert Paul.
AU  - Churchill, Robert Paul.
TI  - Logic: an introduction 
SN  - 0312023537
U1  - 160 
PY  - 1990///
CY  - New York
PB  - St. Martin's Press
KW  - Logic
N1  - Includes bibliographical references and index
ER  -