Babenko, V. F., V. A. Kofanov, and S. A. Pichugov. “On Additive Inequalities for Intermediate Derivatives of Functions Given on a Finite Interval”. Ukrains’kyi Matematychnyi Zhurnal 49, no. 5 (May 25, 1997): 619–628. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/5042.