@article{VKAM_2017_2_a0,
     author = {K. T. Karimov},
     title = {Spectral problems for three-dimensional elliptic equations with singular coefficients},
     journal = {Vestnik KRAUNC. Fiziko-matemati\v{c}eskie nauki},
     pages = {7--19},
     publisher = {mathdoc},
     number = {2},
     year = {2017},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VKAM_2017_2_a0/}
}