@article{FORUM_1996__8_3_141770,
     author = {Jaan Janno},
     title = {Global existence for a hyperbolic integrodifferential inverse problem.},
     journal = {Forum mathematicum},
     pages = {303--318},
     year = {1996},
     volume = {8},
     number = {3},
     zbl = {0851.45009},
     url = {http://geodesic.mathdoc.fr/item/FORUM_1996__8_3_141770/}
}