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@article{DE_1970_6_9_a21, author = {I. N. Astafieva}, title = {Second solutions of equations with positive operators}, journal = {Differencialʹnye uravneni\^a}, pages = {1722--1724}, publisher = {mathdoc}, volume = {6}, number = {9}, year = {1970}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1970_6_9_a21/} }
I. N. Astafieva. Second solutions of equations with positive operators. Differencialʹnye uravneniâ, Tome 6 (1970) no. 9, pp. 1722-1724. http://geodesic.mathdoc.fr/item/DE_1970_6_9_a21/