Kačinskaitė, Roma, and Kohji Matsumoto. “On Mixed Joint Discrete Universality for a Class of Zeta-Functions: A Further Generalization”. Mathematical Modelling and Analysis 25, no. 4 (October 13, 2020): 569-583. Accessed February 25, 2021. https://journals.vgtu.lt/index.php/MMA/article/view/11751.