Joshua Sunday, Chibuisi Chigozie, Ezekiel O. Omole, and John B. Gwong. “A Pair of Three-Step Hybrid Block Methods for the Solutions of Linear and Nonlinear First-Order Systems”. Utilitas Mathematica, vol. 118, Feb. 2021, pp. 1-15, https://utilitasmathematica.com/index.php/Index/article/view/1542.