@article{1183739046, author = {Shore, Richard A.}, title = {$\Sigma\_n$ Sets which are $\Delta\_n$-Incomparable (Uniformly)}, journal = {J. Symbolic Logic}, volume = {39}, number = {1}, year = {1974}, pages = { 295-304}, language = {en}, url = {http://dml.mathdoc.fr/item/1183739046} }
Shore, Richard A. $\Sigma_n$ Sets which are $\Delta_n$-Incomparable (Uniformly). J. Symbolic Logic, Tome 39 (1974) no. 1, pp. 295-304. http://gdmltest.u-ga.fr/item/1183739046/