@article{ZNSL_1975_51_a7,
     author = {K. K. Lavrent'ev},
     title = {Inverse problems of the finding boundary condition in the theory of propagation of nonstationary {waves.~II}},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {129--133},
     publisher = {mathdoc},
     volume = {51},
     year = {1975},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1975_51_a7/}
}