EHIGIE, J. O., S. N. JATOR, and S. A. OKUNUGA. 2017. “A CONTINUOUS RUNGE-KUTTA-NYSTR¨OM COLLOCATION METHOD WITH TRIGONOMETRIC COEFFICIENTS FOR PERIODIC INITIAL VALUE PROBLEMS”. Journal of the Nigerian Mathematical Society 36 (1):139-62. https://ojs.ictp.it/jnms/index.php/jnms/article/view/92.