E. S. Ugulumu and E. L. Inanga, “Tanzania’s small-scale sunflower farmers: Upgrading the value chain”, IJSBAR, vol. 10, no. 1, pp. 126–145, Dec. 2013, Accessed: Dec. 29, 2025. [Online]. Available: https://gssrr.org/JournalOfBasicAndApplied/article/view/1339