Okpara DA, Omaliko CPE. Productivity of yambean (Sphenostylis stenocarpa) - yellow yam (Dioscorea cayenensis) intercropping. Indian J Agri Sci. 2012;65(12). Accessed October 24, 2025. https://epubs.icar.org.in/index.php/IJAgS/article/view/19165