Guelke, Adrian: Rethinking the Rise and Fall of Apartheid, s. 101. Basingstoke: Palgrave Macmillan, 2005. Teoksen verkkoversio (viitattu 18 August 2016).
Hendrik Frensch Verwoerd South African History Online. ”On 5 October 1960 a referendum was held in which White voters were asked "Do you support a republic for the Union?" — 52 percent voted 'Yes'.” Viitattu 11. helmikuuta 2018.