@article{GDZPPN002544636,
title = {Uniform distrubution, positive trigonometric polynomials and difference sets},
journal = {Seminaire de Th\'eorie des Nombres de Bordeaux},
volume = {11},
year = {1981},
pages = {1-18},
zbl = {0515.10048},
url = {http://dml.mathdoc.fr/item/GDZPPN002544636}
}
Ruzsa, Imre Z. Uniform distrubution, positive trigonometric polynomials and difference sets. Seminaire de Théorie des Nombres de Bordeaux, Tome 11 (1981) pp. 1-18. http://gdmltest.u-ga.fr/item/GDZPPN002544636/