Souza, Alessandra Alves de, Hélio Almeida Burity, Márcia do Vale Barreto Figueiredo, Maria Luiza Ribeiro Bastos da Silva, Maeli Melotto, and Siu Mui Tsai. “Symbiotic Efficiency of Hup+, Huphr and Hup- <i>Bradyrhizobium japonicum< i> and <i>Bradyrhizobium elkanii< i> Strains in Cowpea Cultivars”. Pesquisa Agropecuaria Brasileira 34, no. 10 (October 1, 1999): 1925–1931. Accessed July 5, 2026. https://apct.sede.embrapa.br/pab/article/view/5518.