Science for Agriculture and Rural Development in Low-income Countries - Roetter, Reimund P; Keulen, Herman; Laar, H H; Verhagen, Jan; Kuiper, Marijke; Roetter, Reimund P.; Van Keulen, Herman; Keulen, Herman; Kuiper, Marijke; Laar, H H; Verhagen, Jan; van Laar, H. H.; Verhagen, J. (Springer Netherlands, 2007)