Ayamah, R., and K. F. Darkwah. “Factorial Design and Model for the Effect of National Road Safety Strategy Two (NRSS II)”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 20, no. 1, Jan. 2015, pp. 192-07, https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/3183.