Brink, J. A., B. R. Woodward, and E. J. DaSilva. “Plant Biotechnology: A Tool for Development in Africa”. Electronic Journal of Biotechnology, vol. 1, no. 3, Dec. 1998, pp. 0-0, https://preprints.pucv.cl/index.php/ejbiotechnology/article/view/v1n3-6.