@article{FAA_1977_11_1_a4,
     author = {V. I. Feigin},
     title = {The continuous spectrum of differential operators},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {43--54},
     year = {1977},
     volume = {11},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1977_11_1_a4/}
}