@article{CMFD_2007_25_a4,
     author = {S. V. Bochkarev},
     title = {Multiplicative {Bounds} for $L_1${-Norms} of {Exponential} {Sums}},
     journal = {Contemporary Mathematics. Fundamental Directions},
     pages = {49--57},
     publisher = {mathdoc},
     volume = {25},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMFD_2007_25_a4/}
}