@article{SM_2005_196_5_a2,
     author = {Yu. B. Orochko},
     title = {Deficiency indices of a~one-term symmetric differential operator of even order degenerate in the interior of an interval},
     journal = {Sbornik. Mathematics},
     pages = {673--702},
     publisher = {mathdoc},
     volume = {196},
     number = {5},
     year = {2005},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2005_196_5_a2/}
}