@article{SM_1987_58_2_a3,
     author = {N. E. Firsova},
     title = {The direct and inverse scattering problems for the one-dimensional perturbed {Hill} operator},
     journal = {Sbornik. Mathematics},
     pages = {351--388},
     publisher = {mathdoc},
     volume = {58},
     number = {2},
     year = {1987},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1987_58_2_a3/}
}