@article{DE_1987_23_6_a4,
     author = {M. G. Gasymov and A. M. Magerramov},
     title = {Direct and inverse spectral problems for a class of ordinary differential pencils on a finite interval},
     journal = {Differencialʹnye uravneni\^a},
     pages = {960--971},
     publisher = {mathdoc},
     volume = {23},
     number = {6},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1987_23_6_a4/}
}