@article{IVM_2007_6_a5,
     author = {O. A. Koshcheeva},
     title = {Depression conditions for linear equations with major partial derivatives},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {45--54},
     publisher = {mathdoc},
     number = {6},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2007_6_a5/}
}