@article{MZM_1987_41_2_a8,
     author = {V. M. Koltyzhenkov},
     title = {Irregular second-order differential equations with almost-periodic coefficients},
     journal = {Matemati\v{c}eskie zametki},
     pages = {202--206},
     year = {1987},
     volume = {41},
     number = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1987_41_2_a8/}
}