Coulibaly, Ousmane Samba, et al. “Calculation of Error Between the Exact Solution and Solution of Parabolic Equation (Heat Equation) by Krylov Approximation Methods”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 35, no. 1, July 2017, pp. 37-54, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/7752.