BernatskayaJ. N. “Perturbation Method for a Parabolic Equation With Drift on a Riemannian Manifold”. Ukrains’kyi Matematychnyi Zhurnal 56, no. 2 (February 25, 2004): 148-159. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3739.