Je was op zoek naar: unsolvability (Spaans - Engels)

"degrees of unsolvability.
"degrees of unsolvability.

"recursive unsolvability of a problem of thue.
"recursive unsolvability of a problem of thue.

"the upper semi-lattice of degrees of recursive unsolvability.
"the upper semi-lattice of degrees of recursive unsolvability.

"degrees of unsolvability", perspectives in mathematical logic, springer-verlag.
"degrees of unsolvability", perspectives in mathematical logic, springer-verlag.

233-269; reprinted as an appendix in martin davis, "computability and unsolvability", dover reprint 1982.
233–269; reprinted as an appendix in martin davis, "computability and unsolvability", dover reprint 1982.

1968 (with hilary putnam), "degrees of unsolvability of constructible sets of integers," "journal of symbolic logic 33": 497-513.
* 1968 (with hilary putnam), "degrees of unsolvability of constructible sets of integers," "journal of symbolic logic 33": 497-513.