Dube S, Kurwa F, Chawira G, Hallett TB, Gregson S, Mason PR, Garnett GP
Bull World Health Organ, 2010 ; 88 : 761-8
Anderson RM, Chandiwana SK, Gregson S, Terceira N, Kakowa M, Mason PR
AIDS, 2002 ; 16(4) : 643-52