TY  - BOOK
AU  - Shoenfield,Joseph R.
TI  - Degrees of unsolvability
U1  - 512.8 
PY  - 1972///
CY  - Amsterdam
PB  - North-Holland Pub.
KW  - Logic, Symbolic and mathematical
KW  - Recursive functions
KW  - Unsolvability (Mathematical logic)
ER  -