Ajayi, Abiola Toyin. “Relationships Among Drought Tolerance Indices and Yield Characters of Cowpea (Vigna Unguiculata L. Walp)”. International Journal of Scientific Research in Biological Sciences, vol. 7, no. 5, Oct. 2020, pp. 93-103, https://ijsrbs.isroset.org/index.php/j/article/view/404.