By C. Broertjes, A.M.Van Harten
By Donald Grierson
By Professor Dr. Y. P. S. Bajaj
By Mary Anderson (Universitat Heidelberg, Germany), Jeremy Roberts (Univ of Nottingham, UK)
By Ian Scoones
By Bozzano G Luisa
By J.H.C. Gash, etc., C.A. Nobre (Centro de Provisio de Temp e Estudos Climaticos, Brazil), J.M. Roberts (Institute of Hydrology, UK), R.L. Victoria (Centro de Energia Nuclear na Agricultura
By Sterling A. Taylor, Gaylen L. Ashcroft
By C. Johansen, etc.
By Karl Maramorosch, Kerry F. Harris
By Adel A Kader
By K A Longman, R H F Wilson
By John Edmonds
By Nuri N. Mohsenin
By W.G. Burton
By P. D. Hebblethwaite
By Christian Bonte-Friedheim, Kathleen Sheridan, International Service for Agricultural Research (ISNAR)
By E.M. Aitchison, D.L. Hawksworth
By Geoffrey Clough Ainsworth
By D. Walkey
By Marko Koscak, Tony O'Rourke
By Niko Roorda
By Margaret Somerville
By P.M. Harris
By Paul Micklethwaite
By J.M. Thresh