TY  - BOOK
AU  - Langer,Susanne K.
TI  - An introduction to symbolic logic
U1  - 511.3  
PY  - 1953///
CY  - New York, London
PB  - Dover, Constable
KW  - Logic, Symbolic and mathematical
N1  - Bibliography: p. 356-360; Includes index
ER  -