@article{ZNSL_1997_239_a9,
     author = {A. P. Kiselev and M. V. Perel'},
     title = {On the nature of ``quasiphotons''},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {117--122},
     publisher = {mathdoc},
     volume = {239},
     year = {1997},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1997_239_a9/}
}