Sait-Ametov, M. R., and A. N. Kochubei. 2005. “Remarks on the Green Functions of Elliptic Pseudo-Differential Operators over the Field of $p$-Adic Numbers”. Methods of Functional Analysis and Topology 11 (1): 60-62. https://zen.imath.kiev.ua/index.php/mfat/article/view/266.