Slezeviciene, R. and Steading, J. (2004) “On Exponential Sums Related to the Circle Problem”, Ukrains’kyi Matematychnyi Zhurnal, 56(10), pp. 1405–1418. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/3853 (Accessed: 5 December 2025).