@article{IVM_1984_6_a9,
     author = {A. L. Teptin},
     title = {The sign of the {Green} function of a~boundary value problem},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {53--55},
     publisher = {mathdoc},
     number = {6},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1984_6_a9/}
}