Jain, P. K., and S. K. Kaushik. “On It-Shrinking And A-Boundedly Complete M-BASES in Banach Spaces”. The Journal of the Indian Mathematical Society, vol. 54, no. 1-4, Dec. 1989, pp. 147-54, https://informaticsjournals.co.in/index.php/jims/article/view/21883.