@article{MZM_2006_80_6_a5,
     author = {A. M. Savchuk and A. A. Shkalikov},
     title = {On the eigenvalues of the {Sturm{\textendash}Liouville} operator with potentials from {Sobolev} spaces},
     journal = {Matemati\v{c}eskie zametki},
     pages = {864--884},
     year = {2006},
     volume = {80},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2006_80_6_a5/}
}