@article{DE_1985_21_6_a25,
     author = {Yu. A. Konyaev},
     title = {Sequential analysis of periodic systems with a small parameter multiplying the derivative in the presence of purely imaginary (including identically multiple) points in the spectrum of the limit operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1085--1089},
     publisher = {mathdoc},
     volume = {21},
     number = {6},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1985_21_6_a25/}
}