Koorts, Alida Maria; Levay, Peter Ferenc; Hall, Alan Norman; Van der Merwe, Christiaan Frederick; Becker, Piet J.; Frantzen, Doron Johan Manuel; Viljoen, Margaretha(Sage, 2012)
Repsold, Lisa; Pool, Roger; Karodia, Mohammed; Tintinger, Gregory; Becker, Piet J.; Joubert, Anna Margaretha(Faculty of Health Sciences, University of Pretoria, 2021)