@article{DAN_1980_252_2_a4,
     author = {M. G. Gasymov},
     title = {Spectral analysis of a class of ordinary differential operators with periodic coefficients},
     journal = {Doklady Akademii Nauk},
     pages = {277--280},
     publisher = {mathdoc},
     volume = {252},
     number = {2},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_252_2_a4/}
}