@article{FAA_1967_1_2_a9,
     author = {P. P. Zabreiko and R. I. Kachurovskii and M. A. Krasnosel'skii},
     title = {On a fixed-point principle for operators in a {Hilbert} space},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {93--94},
     publisher = {mathdoc},
     volume = {1},
     number = {2},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1967_1_2_a9/}
}