Walton, J. (1974). Watermills, windmills and horse-mills of South Africa (1ª ed.). Cape Town and Johannesburg: C. Struik.
Cita MLA (8 ed.) (Copiar al portapapeles)Walton, James. Watermills, Windmills and Horse-mills of South Africa. 1ª ed. Cape Town and Johannesburg: C. Struik , 1974.