Rukasov, V. I. and Chaichenko, S. O. (2010) “Approximation by de la Vallée-Poussin operators on the classes of functions locally summable on the real axis”, Ukrains’kyi Matematychnyi Zhurnal, 62(7), pp. 968–978. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/2929 (Accessed: 29March2024).