@article{DE_1986_22_1_a11,
     author = {M. Rakhimov},
     title = {The property of being an unconditional basis on a closed interval of systems of eigen- and associated functions of a quadratic pencil of nonselfadjoint differential operators},
     journal = {Differencialʹnye uravneni\^a},
     pages = {94--103},
     publisher = {mathdoc},
     volume = {22},
     number = {1},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1986_22_1_a11/}
}