TY  - BOOK
AU  - Sacks, Gerald E
TI  - Degrees of unsolvability
SN  - 9780691079417
SN  - 63009996
U1  - 517.5 SAC 
PY  - 1963///
CY  - Princeton, N.J
PB  - Princeton University Press
KW  - Recursive functions
KW  - Unsolvability (Mathematical logic)
N1  - Bibliography: p. 173-174
ER  -