PACHPATTE, B. G. “A MANY VARIABLE GENERALIZATION OF HARDY’S INEQUALITY CONCERNING A SERIES OF TERMS”. Tamkang Journal of Mathematics 23, no. 4 (December 1, 1992): 349–354. Accessed April 25, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4558.