International Institute of Tropical Agriculture. (1980). IITA root and tuber improvement program: staff papers 1977/78. Ibadan, Nigeria: IITA, (p. 33).
ICRISAT, - (2009) Guinea-race Sorghum Hybrids: Bringing the benefits of hybrid technology to a staple crop in Africa. Documentation. International Crops Research Institute for the Semi-Arid Tropics, Patancheru, Andhra Pradesh, India
de Wasseige, C., Tadoum M., Ebaa-Atyi, R., Doumenge, C., (eds.). 2015. The Forests of the Congo Basin : Forests and climate change. : 128p. Belgium: Weyrich.