@article{FAA_1983_17_1_a12,
     author = {M. A. Krasnosel'skii and A. V. Sobolev},
     title = {Spectral clearance of a focusing operator},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {73--74},
     publisher = {mathdoc},
     volume = {17},
     number = {1},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1983_17_1_a12/}
}