@article{10_4064_ba57_2_2,
     author = {Igor E. Shparlinski},
     title = {Exponential {Sums} with {Farey} {Fractions}},
     journal = {Bulletin of the Polish Academy of Sciences. Mathematics},
     pages = {101--107},
     publisher = {mathdoc},
     volume = {57},
     number = {2},
     year = {2009},
     doi = {10.4064/ba57-2-2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ba57-2-2/}
}