@article{DE_2000_36_1_a16,
     author = {D. V. Il'in},
     title = {The {Schr\"odinger} operator with a $\delta$-potential: {The} case of degenerate resonances},
     journal = {Differencialʹnye uravneni\^a},
     pages = {124--126},
     year = {2000},
     volume = {36},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2000_36_1_a16/}
}