ß-carotene–rich orange-fleshed sweet potato improves the vitamin A status of primary school children assessed with the modified-relative-dose-response test - van Jaarsveld P. J.; Faber, M.; Tanumihardjo, S. A.; Nestel, Penelope; Lombard C. J.; Spinnler Benadé A. J. (Elsevier, 2005)