Dũng, H. Đình, and V. T. Ngọc. “Difference Schemes for Weak Solutions of Mixed Problem for a Class of Parabolic Differential Equations I”. Journal of Computer Science and Cybernetics, vol. 19, no. 1, July 2012, pp. 91-99, doi:10.15625/1813-9663/19/1/1524.