@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/