Ploymukda, Arnon, and Pattrawut Chansangiam. “Geometric Means and Tracy-Singh Products for Positive Operators”. Communications in Mathematics and Applications 9, no. 4 (September 26, 2018): 475–488. Accessed May 3, 2024. http://www.rgnpublications.com/journals/index.php/cma/article/view/547.