@article{DE_1986_22_3_a1,
     author = {B. F. Bylov and \`E. A. Tikhonova},
     title = {Exponents of certain second-order differential equations with piecewise-constant matrix},
     journal = {Differencialʹnye uravneni\^a},
     pages = {378--389},
     publisher = {mathdoc},
     volume = {22},
     number = {3},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1986_22_3_a1/}
}