YANG, GOU-SHENG, and KAI-YU TENG. “A GENERALIZATION OF INVERSE SCHWARZ’S INEQUALITY”. Tamkang Journal of Mathematics 23, no. 2 (June 1, 1992): 117–121. Accessed April 25, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4534.