OKELEYE, K A; OKELANA, M A O. Effect of phosphorus fertilizer on nodulation, growth and yield of cowpea (Vigna unguiculata) varieties. The Indian Journal of Agricultural Sciences, Delhi, India, v. 67, n. 1, 2013. Disponível em: https://epubs.icar.org.in/index.php/IJAgS/article/view/29823. Acesso em: 29 oct. 2025.