Variations in yield gaps of smallholder cocoa systems and the main determining factors along a climate gradient in Ghana - Abdulai, Issaka; Hoffmann, Munir P.; Jassogne, Laurence T.P.; Asare, Richard; Graefe, Sophie; Hsiao-Hang, Tao; Muilerman, Sander; Vaast, Philippe; Asten, Piet J.A. van; Läderach, Peter R.D.; Rötter, Reimund P. (Elsevier, 2020)