@article{IVM_1968_10_a2,
     author = {A. N. Veissenberg and B. I. Kushchev},
     title = {A~certain criterion for instability in the critical case with an even number of zero roots},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {17--20},
     publisher = {mathdoc},
     number = {10},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1968_10_a2/}
}