PEARCE, C. E. M., and J. PECARIC. “ON HUA’S INEQUALITY FOR COMPLEX NUMBERS”. Tamkang Journal of Mathematics 28, no. 3 (September 1, 1997): 193–199. Accessed March 28, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4314.