@article{DE_2006_42_10_a14,
     author = {B. T. Bilalov and S. G. Veliev},
     title = {Bases of eigenfunctions of two discontinuous differential operators},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1428--1430},
     publisher = {mathdoc},
     volume = {42},
     number = {10},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2006_42_10_a14/}
}