Kuttner, B. “Note on a Paper by M. S. Ramanujan on Quasi-Hausdorff Transformations”. The Journal of the Indian Mathematical Society 21, no. 3-4 (December 1, 1957): 97–104. Accessed May 10, 2024. http://www.informaticsjournals.com/index.php/jims/article/view/16962.