@article{ZVMMF_2009_49_2_a6,
     author = {M. D. Malykh},
     title = {On the emptiness criteria for the discrete spectrum of the {Dirichlet} problem for the equation},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {288--292},
     publisher = {mathdoc},
     volume = {49},
     number = {2},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_2009_49_2_a6/}
}