@ARTICLE {CARDWELL:1997a, title = {A systems approach to assess crop health and maize yield lossess due to pests and diseases in Cameroon}, author = {Cardwell, K. and Schulthess, F. and Ndemah, R. and Ngoko, Z. }, journal = {Agriculture, Ecosystems and Environment}, year = {1997}, volume = {65}, number = {1}, pages = {33--47}, issn = {0167-8809}, }