@article{MZM_2003_73_1_a16,
     author = {N. A. Sidel'nikova},
     title = {Deficiency {Indices} of the {Singular} {Differential} {Operator} {Generated} by the {Expression} $y^{\mathrm{IV}}-2a(x^\alpha y')'+bx^\beta y$},
     journal = {Matemati\v{c}eskie zametki},
     pages = {153--156},
     publisher = {mathdoc},
     volume = {73},
     number = {1},
     year = {2003},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2003_73_1_a16/}
}