@article{ZNSL_1982_115_a23,
     author = {D. R. Yafaev},
     title = {Nonstationary scattering theory for elliptic differential operators},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {285--300},
     publisher = {mathdoc},
     volume = {115},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1982_115_a23/}
}