Voir la notice de l'article provenant de la source Math-Net.Ru
@article{AL_1973_12_6_a6, author = {L. Hay}, title = {Index sets in $O\,'$}, journal = {Algebra i logika}, pages = {713--729}, publisher = {mathdoc}, volume = {12}, number = {6}, year = {1973}, language = {en}, url = {http://geodesic.mathdoc.fr/item/AL_1973_12_6_a6/} }
L. Hay. Index sets in $O\,'$. Algebra i logika, Tome 12 (1973) no. 6, pp. 713-729. http://geodesic.mathdoc.fr/item/AL_1973_12_6_a6/