Osseo-Asare, Abena Dove Agyepoma Bitter roots : the search for healing plants in Africa The University of Chicago Press, 2014

http://press.uchicago.edu/ucp/books/book/chicago/B/bo17031345.html

http://books.google.fr/books?id=exs7AgAAQBAJ&pg=PR4&lpg=PR4&dq=Osseo-Asare,+Abena+Dove+Agyepoma+Bitter+roots+:+the+search+for+healing+plants+in+Africa&source=bl&ots=iTJ2FBBbPH&sig=INoHtUwKcUct8-0rHFTQ1kvtk_w&hl=fr&sa=X&ei=3GbnU_KMGeOr0QXfsYDoAg&ved=0CDQQ6AEwAg#v=onepage&q=Osseo-Asare%2C%20Abena%20Dove%20Agyepoma%20Bitter%20roots%20%3A%20the%20search%20for%20healing%20plants%20in%20Africa&f=false