@article{ZNSL_1976_62_a9,
     author = {A. P. Katchalov},
     title = {Some equations for the problem of diffraction by a convex shell},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {124--125},
     year = {1976},
     volume = {62},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1976_62_a9/}
}