@article{DAN_1960_131_5_a4,
     author = {D. F. Davidenko},
     title = {The method of variation of parameters as applied to the computation of eigenvalues and eigenvectors of matrices},
     journal = {Doklady Akademii Nauk},
     pages = {1007--1010},
     publisher = {mathdoc},
     volume = {131},
     number = {5},
     year = {1960},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1960_131_5_a4/}
}