BARICZ, Árpád, and Tibor K. POGÁNY. “Extension of Karamata Inequality for Generalized Inverse Trigonometric Functions”. Studia Universitatis Babeș-Bolyai Mathematica, vol. 60, no. 3, Sept. 2015, pp. 379-84, https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/5773.