C. W. Njiru, S. C. Letema, and S. M. Maingi, “Socio-Economic Factors of Small Hydropower and Biogas Plants and their Implications for Rural Energy Poverty Alleviation in Kirinyaga, Kenya”, JNRD, vol. 8, pp. 101–114, Oct. 2018, doi: 10.5027/jnrd.v8i0.10.