@article{IVM_1958_3_a31,
     author = {E. S. Chichkin},
     title = {The non-oscillation problem for linear equations of fourth order},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {248--250},
     year = {1958},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1958_3_a31/}
}