Babenko, V.F. and Ligun, A.A. (1993) “Some Bernstein-type inequalities for trigonometric polynomials”, Ukrains’kyi Matematychnyi Zhurnal, 45(3), pp. 428–430. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5825 (Accessed: 5 December 2025).