SkaskivO. B., and TrakaloO. M. “On the Stability of the Maximum Term of the Entire Dirichlet Series”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 57, no. 4, Apr. 2005, pp. 571–576, https://umj.imath.kiev.ua/index.php/umj/article/view/3623.