2 citations to https://www.mathnet.ru/eng/dan32383
  1. M. N. Dobrovolskii, “Kvazipolnye korotkie kubicheskie trigonometricheskie summy”, Chebyshevskii sb., 10:1 (2009), 9–30  mathnet  mathscinet
  2. D. A. Mit'kin, “On estimates and asymptotic formulas for rational trigonometric sums that are almost complete”, Math. USSR-Sb., 50:2 (1985), 513–532  mathnet  crossref  mathscinet  zmath