TAIWO, O. P.; NWONUALA, A. I.; I. B., F. Variability in Yield and Yield Components of Selected Pro-vitamin A Maize (Zea mays L.) Varieties in a Humid Environment of Port Harcourt, Nigeria. Asian Journal of Agricultural and Horticultural Research, v. 5, n. 3, p. 1-10, 19 mar. 2020.