Andrica, D., and I. Raşa. “The Jensen Inequality: Refinements and Applications”. Anal. Numér. Théor. Approx. 14, no. 2 (August 1, 1985): 105–108. Accessed November 22, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1985-vol14-no2-art1.