@article{DAN_1991_319_5_a2,
     author = {N. S. Bojinov},
     title = {Sufficient conditions for the basis property, convergence and summability of the root expansion of a nonlocal {Sturm{\textendash}Liouville} problem},
     journal = {Doklady Akademii Nauk},
     pages = {1042--1047},
     year = {1991},
     volume = {319},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_319_5_a2/}
}