Pecaric, J., and S. Varosanec. “A Note on Simpson’s Inequality for Functions of Bounded Variation”. Tamkang Journal of Mathematics 31, no. 3 (September 30, 2000): 239–242. Accessed March 29, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/398.