Shekhar, Abhisekh, and Nawin Agrawal. “Generalized Pseudo-Differential Operators Associated With Symbol Classes Involving Fractional Fourier Transform”. Serdica Mathematical Journal 48, no. 4 (October 15, 2022): 247–270. Accessed October 23, 2026. https://serdica.math.bas.bg/index.php/serdica/article/view/53.