Terblanche, A., A. Lang, C. Gray, E. Goddard, S. Karabus, M. Kriel, A. Manjra, S. Risenga, D. van der Spuy, and M. Levin. “Non-IgE-Mediated Food Allergies”. South African Medical Journal, vol. 105, no. 1, Mar. 2015, p. 66, https://www.ajol.info/index.php/samj/article/view/113971.