Siebörger, R. F. (1975). The recruitment and organization of African labor for the Kimberley Diamond Mines, 1871-1888.
Lua i Stíl Chicago (17ú heag.)Siebörger, Robert Frederick. The Recruitment and Organization of African Labor for the Kimberley Diamond Mines, 1871-1888. 1975.
Lua MLA (8ú heag.)Siebörger, Robert Frederick. The Recruitment and Organization of African Labor for the Kimberley Diamond Mines, 1871-1888. 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.