LitovchenkoV. A., and StrybkoO. V. “Principle of Localization of Solutions of the Cauchy Problem for One Class of Degenerate Parabolic Equations of Kolmogorov Type”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 62, no. 11, Nov. 2010, pp. 1473–1489, https://umj.imath.kiev.ua/index.php/umj/article/view/2972.