TY  - BOOK
AU  - Snyder, D. Paul,
AU  - 
ED  - 
ED  - 
ED  - 
ED  - 
SN  - 2
PY  - 1971///46
CY  - New York
PB  - Van Nostrand Reinhold
KW  - 
KW  - 2
KW  - 0
KW  - 6
KW  - 20
KW  - Modality (Logic)
N1  - Bibliography: p. 325; 5
ER  -