@article{IVM_1962_6_a15,
     author = {G. A. Freiman},
     title = {Inverse problems of additive number theory. {VII.} {The} addition of finite sets. {IV.} {The} method of trigonometric sums},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {131--144},
     publisher = {mathdoc},
     number = {6},
     year = {1962},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1962_6_a15/}
}