Ballantine, Christopher (1999). "Looking to the USA: the politics of male close-harmony song style in South Africa during the 1940s and 1950s". Popular Music. 18 (1). Cambridge University Press (CUP): 1–17. doi:10.1017/s0261143000008709. ISSN0261-1430.
Ballantine, Christopher (1999). "Looking to the USA: the politics of male close-harmony song style in South Africa during the 1940s and 1950s". Popular Music. 18 (1). Cambridge University Press (CUP): 1–17. doi:10.1017/s0261143000008709. ISSN0261-1430.