Okpon, S. N., & Aduayi, E. A. (2014). Nitrogen Nutrition of White Yam (Dioscorea rotundata Poir) Grown in Two Selected Locations of Southwestern Nigeria. Obafemi Awolowo University.
Chicago-referens (17:e uppl.)Okpon, Stephen Nelson, och E. A. Aduayi. Nitrogen Nutrition of White Yam (Dioscorea Rotundata Poir) Grown in Two Selected Locations of Southwestern Nigeria. Obafemi Awolowo University, 2014.
MLA-referens (9:e uppl.)Okpon, Stephen Nelson, och E. A. Aduayi. Nitrogen Nutrition of White Yam (Dioscorea Rotundata Poir) Grown in Two Selected Locations of Southwestern Nigeria. Obafemi Awolowo University, 2014.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.