About Ralph Callebert Books by Ralph Callebert Entrepreneurship in Africa A Historical Approach edited by Moses E. Ochonu contributions by Ralph Callebert, Chambi Chachage, Gloria Chuku, Gloria Emeagwali, Michael Gennaro, Kwasi Konadu, Isidore Lobnibe, Marta Musso, Mike Odugbo Odey, Lynn Schler, Martin Shanguhyia & Uyilawa Usuanlele