@article{ZNSL_2003_303_a5,
     author = {E. Doubtsov},
     title = {Weakly cyclic vectors with a~given modulus},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {111--118},
     year = {2003},
     volume = {303},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2003_303_a5/}
}