Gurjinder Singh and Higinio Ramos. (2018). An Optimized Two-Step Hybrid Block Method Formulated in Variable Step-Size Mode for Integrating $y''=f(x,y,y')$ Numerically.
Numerical Mathematics: Theory, Methods and Applications. 12 (2).
640-660.
doi:10.4208/nmtma.OA-2018-0036