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@article{DE_1988_24_6_a25, author = {A. L. Teptin}, title = {A new condition for the sign-constancy of the {Green} function}, journal = {Differencialʹnye uravneni\^a}, pages = {1066--1069}, publisher = {mathdoc}, volume = {24}, number = {6}, year = {1988}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1988_24_6_a25/} }
A. L. Teptin. A new condition for the sign-constancy of the Green function. Differencialʹnye uravneniâ, Tome 24 (1988) no. 6, pp. 1066-1069. http://geodesic.mathdoc.fr/item/DE_1988_24_6_a25/