Antoniouk, A. Vict., and A. Val. Antoniouk. 2001. “Higher-Order Relations for Derivatives of Nonlinear Diffusion Semigroups”. Ukrains’kyi Matematychnyi Zhurnal 53 (1): 117-22. https://umj.imath.kiev.ua/index.php/umj/article/view/4227.