@article{DAN_1994_334_2_a2,
     author = {Yu. F. Dolgii},
     title = {Representation of the monodromy operator in the form of the sum of},
     journal = {Doklady Akademii Nauk},
     pages = {138--140},
     publisher = {mathdoc},
     volume = {334},
     number = {2},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1994_334_2_a2/}
}