@article{DAN_1969_189_5_a12,
     author = {R. F. Fikhmanas and P. Sh. Fridberg},
     title = {Two-sided variation estimates for polarizability coefficients in the theory of diffraction at small apertures},
     journal = {Doklady Akademii Nauk},
     pages = {969--972},
     publisher = {mathdoc},
     volume = {189},
     number = {5},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1969_189_5_a12/}
}