Chen, C., and Z.-H. Zhou. “Differences of the Weighted Differentiation Composition Operators from Mixed-Norm Spaces to Weighted-Type Spaces”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 68, no. 6, June 2016, pp. 842-5, http://umj.imath.kiev.ua/index.php/umj/article/view/1883.