s:211:"%T Soil heterogeneity and soil fertility gradients in smallholder farms of the East African highlands 
%A Tittonell, P. 
%A Muriuki, A. 
%A Klapwijk, C.J. 
%A Shepherd, K.D. 
%A Coe, R. 
%A Vanlauwe, B. 
";