@article{ZNSL_1975_51_a13,
     author = {N. E. Firsova},
     title = {Rieman surface of quasiimpulse and the theory of scattering for disturbed {Hill} operator},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {183--196},
     publisher = {mathdoc},
     volume = {51},
     year = {1975},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1975_51_a13/}
}