Samat, Nor Azah, and Aznida Che Awang. “The Discrete Time-Space SIR-SI Age-Structured Model for Leptospirosis”. International Journal of Engineering & Technology, vol. 7, no. 4.30, Nov. 2018, pp. 484-7, https://doi.org/10.14419/ijet.v7i4.30.22374.