du Plessis, L., P. van der Merwe, and M. Saayman. “Tourists’ Perceptions on Whether South African National Parks Are Environmentally Friendly”. Acta Academica: Critical Views on Society, Culture and Politics, vol. 45, no. 1, Jan. 2013, pp. 187-08, doi:10.38140/aa.v45i1.1394.