TY  - BOOK
AU  - Langer,Susanne Katherina Knauth
TI  - An introduction to symbolic logic
AV  - BC135 .L35 1953
U1  - 164 
PY  - 1953///
CY  - New York
PB  - Dover Publications
KW  - Logic, Symbolic and mathematical
KW  - Local
N1  - Bibliography: p. 356-360
ER  -