T. Dhansay, C. Musekiwa, T. Ntholi, L. Chevallier, D. Cole, and M. J. de Wit, “South Africa’s geothermal energy hotspots inferred from subsurface temperature and geology”, S. Afr. J. Sci., vol. 113, no. 11/12, p. 7, Nov. 2017, doi: 10.17159/sajs.2017/20170092.