James Barber, Angela Fung, Sandeep Toshniwal, Becky Voorheis, and Campbell R. Harvey, Telkom, South Africa", Winter (1999).
2008년 11월 23일에 확인함.  James Barber, Angela Fung, Sandeep Toshniwal, Becky Voorheis, and Campbell R. Harvey, Telkom, South Africa", Winter (1999).