@article{ZNSL_2001_282_a6,
     author = {A. P. Kalupin and V. L. Oleinik},
     title = {A lemniscate as the spectrum of a~perturbed shift},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {74--91},
     publisher = {mathdoc},
     volume = {282},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2001_282_a6/}
}