@article{ZNSL_1971_23_a10,
     author = {N. K. Nikol'skii},
     title = {Five problems about invariant subspaces},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {115--127},
     year = {1971},
     volume = {23},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1971_23_a10/}
}