Reshetukha, I.V. (1971) “Generalized sums for characters and their applications to the reciprocity laws ”, Ukrains’kyi Matematychnyi Zhurnal, 23(2), pp. 270–276. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/8514 (Accessed: 10 April 2025).