@article{ZNSL_2004_318_a6,
     author = {A. Eden and V. K. Kalantarov},
     title = {On global behavior of solutions to an inverse problem for semi-linear hyperbolic equations},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {120--134},
     publisher = {mathdoc},
     volume = {318},
     year = {2004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2004_318_a6/}
}