Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DAN_1974_218_2_a14, author = {S. V. Yablonskii}, title = {The structure of the upper neighborhood for predicate-describable classes in $P_k$}, journal = {Doklady Akademii Nauk}, pages = {304--307}, publisher = {mathdoc}, volume = {218}, number = {2}, year = {1974}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1974_218_2_a14/} }
S. V. Yablonskii. The structure of the upper neighborhood for predicate-describable classes in $P_k$. Doklady Akademii Nauk, Tome 218 (1974) no. 2, pp. 304-307. http://geodesic.mathdoc.fr/item/DAN_1974_218_2_a14/