TY  - BOOK
AU  - Worrall John
AU  - Zahar Elie ed.
TI  - Proofs and refutations : the logic of mathematical discovery
SN  - 0-521-21078-X
U1  - 511.3 
PY  - 1976///
CY  - Cambridge
PB  - C U P
KW  - Mathematical logic
KW  - Proof theory
ER  -