@article{IVM_1993_5_a9,
     author = {T. A. Osechkina},
     title = {Unique solvability and sign constancy of the {Green} function of a~periodic boundary value problem for a~linear equation with deviating argument},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {86--94},
     publisher = {mathdoc},
     number = {5},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1993_5_a9/}
}