@article{ZNSL_2009_370_a11,
     author = {D. Chelkak},
     title = {An application of the fixed point theorem to the inverse {Sturm--Liouville} problem},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {203--218},
     publisher = {mathdoc},
     volume = {370},
     year = {2009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2009_370_a11/}
}