@article{IIMI_2004_1_a2,
     author = {L. I. Danilov},
     title = {On absence of eigenvalues in the spectra of two-dimensional periodic {Dirac} and {Schr\"odinger} operators},
     journal = {Izvestiya Instituta Matematiki i Informatiki Udmurtskogo Gosudarstvennogo Universiteta},
     pages = {49--84},
     year = {2004},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IIMI_2004_1_a2/}
}