@article{IVM_1999_2_a8,
     author = {Yu. V. Pokornyi and R. Mustafokulov},
     title = {On the positivity of the {Green} function of linear boundary value problems for fourth-order equations on a~graph},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {75--82},
     publisher = {mathdoc},
     number = {2},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1999_2_a8/}
}