Janulis, K., A. Laurinčikas, R. Macaitienė, and D. Šiaučiūnas. “Joint Universality of Dirichlet L-Functions and Periodic Hurwitz Zeta-Functions”. Mathematical Modelling and Analysis, vol. 17, no. 5, Nov. 2012, pp. 673-85, doi:10.3846/13926292.2012.735260.