Gitunga, R. M., J. Koske K., and J. Mutiso M. “Applying the Polynomial Model in Simplex”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 31, no. 1, Jan. 2017, pp. 101-17, https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/6676.