Laurinčikas, Antanas, and Monika Tekorė. “Joint Universality of Periodic Zeta-Functions With Multiplicative Coefficients”. Nonlinear Analysis: Modelling and Control 25, no. 5 (September 1, 2020): 860–883. Accessed October 2, 2022. https://www.journals.vu.lt/nonlinear-analysis/article/view/19278.