S. Z. Rida, A. S. Abd El Radi, A. Arafa, and M. Khalil, “The effect of the environmental parameter on the Hantavirus infection through a fractional-order SI model”, IJBAS, vol. 1, no. 2, pp. 88–99, May 2012, doi: 10.14419/ijbas.v1i2.26.