ZhangR. R. “Value Distribution of Differential-Difference Polynomials of Meromorphic Functions”. Ukrains’kyi Matematychnyi Zhurnal 70, no. 4 (April 25, 2018): 471-480. Accessed December 5, 2020. http://umj.imath.kiev.ua/index.php/umj/article/view/1569.