Raweesawat, K., Y. Areepong, S. Sukparungsee, and K. Jampachaisri. “Odds Ratio Estimation for Small Proportion in Binomial Distribution”. Asian Journal of Applied Sciences, vol. 4, no. 1, Feb. 2016, https://www.ajouronline.com/index.php/AJAS/article/view/3672.