@article{MZM_2004_76_2_a12,
     author = {O. A. Romanova and Ya. T. Sultanaev},
     title = {Spectral {Properties} of {Differential} {Operators} of {Order~}$2N$},
     journal = {Matemati\v{c}eskie zametki},
     pages = {303--307},
     publisher = {mathdoc},
     volume = {76},
     number = {2},
     year = {2004},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2004_76_2_a12/}
}