IVASYSHEN, S. D.; LAYUK, V. V. Fundamental solutions of the Cauchy problem for some degenerate parabolic equations of the Kolmogorov type. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 63, n. 11, p. 1469–1500, 2011. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2819. Acesso em: 7 apr. 2025.