@article{Tittonell_2008,
title={Yield gaps,
nutrient use efficiencies and response to fertilisers by maize across heterogeneous smallholder farms of western Kenya},
volume={313},
ISSN={1573-5036},
url={http://dx.doi.org/10.1007/s11104-008-9676-3},
DOI={10.1007/s11104-008-9676-3},
number={1–2},
journal={Plant and Soil},
publisher={Springer Science and Business Media LLC},
author={Tittonell,
P. and Vanlauwe,
B. and Corbeels,
M. and Giller,
K. E.},
year={2008},
month=aug,
pages={19–37} }