Balčiūnas, A., Garbaliauskienė, V., Karaliūnaitė, J., Macaitienė, R., Petuškinaitė, J. and Rimkevičienė, A. 2020. Joint discrete approximation of a pair of analytic functions by periodic zeta-functions. Mathematical Modelling and Analysis. 25, 1 (Jan. 2020), 71-87. DOI:https://doi.org/10.3846/mma.2020.10450.