@article{GDZPPN002297418,
title = {Diophantine Approximation and Sums of Roots of Unity.},
journal = {Mathematische Annalen},
volume = {174},
year = {1967},
pages = {118-135},
zbl = {0139.27702},
url = {http://dml.mathdoc.fr/item/GDZPPN002297418}
}
DAVENPORT, H.; SCHINZEL, A. Diophantine Approximation and Sums of Roots of Unity.. Mathematische Annalen, Tome 174 (1967) pp. 118-135. http://gdmltest.u-ga.fr/item/GDZPPN002297418/