@article{1183734988, author = {Hensel, Gustav B.}, title = {Review: Gerald E. Sacks, Degrees of Unsolvability}, journal = {J. Symbolic Logic}, volume = {29}, number = {1}, year = {1964}, pages = { 202-203}, language = {en}, url = {http://dml.mathdoc.fr/item/1183734988} }
Hensel, Gustav B. Review: Gerald E. Sacks, Degrees of Unsolvability. J. Symbolic Logic, Tome 29 (1964) no. 1, pp. 202-203. http://gdmltest.u-ga.fr/item/1183734988/