@article{1183741145, author = {Weitkamp, Galen}, title = {Analytic Sets Having Incomparable Kleene Degrees}, journal = {J. Symbolic Logic}, volume = {47}, number = {1}, year = {1982}, pages = { 860-868}, language = {en}, url = {http://dml.mathdoc.fr/item/1183741145} }
Weitkamp, Galen. Analytic Sets Having Incomparable Kleene Degrees. J. Symbolic Logic, Tome 47 (1982) no. 1, pp. 860-868. http://gdmltest.u-ga.fr/item/1183741145/