@article{DE_1981_17_12_a20,
     author = {A. L. Teptin},
     title = {On the sign of the {Green} function of a difference boundary value problem},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2283--2286},
     publisher = {mathdoc},
     volume = {17},
     number = {12},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1981_17_12_a20/}
}