A. Rahimi, M. H. Faroughi, and M. R. Abdollahpour, “$pg$-frame in Banach spaces”, MFAT, vol. 13, no. 3, pp. 201–210, Sep. 2007, Accessed: Feb. 04, 2026. [Online]. Available: https://zen.imath.kiev.ua/index.php/mfat/article/view/349