Kaushik, S. K., and Raj Kumar. “On $\boldsymbol{k}$-Deficit Banach Frames. Armenian Journal of Mathematics”. Armenian Journal of Mathematics 2, no. 4 (December 29, 2009): 146–154. Accessed May 9, 2026. http://test.armjmath.sci.am/index.php/ajm/article/view/62.