By L. R. Humphreys
By Williams, Colin Norman, Chen, W.Y., Chew, Rajaratnam, J.A.
By James L. Brewster (Horticulture Research International, Wellesbourne, UK)
By B C Anochili
By S. J. Kays
By Agriculture, Fish.& Food, Min.of
By N.T. Gill, K.C. Vear
By J.D. Acland
By S.C. Pearce
By Food and Agriculture Organization of the United Nations
By M. N. Clifford, K. C. Willson
By David H. Nobel, Charles P. Course
By G. M. Craig (Research Fellow, Centre for Agricultural Strategy, University of Reading)
By Dennis S. Hill, J. M. Waller
By R. Webster
By J.M. Hodgson
By Roger Balls
By Melvyn Kay
By Raymond A. T. George
By Anne Van den Ban, H.S. Hawkins, A.W. van den Ban
By L. T. Evans
By Jackson, Lucy
By Great Britain: Agricultural Development and Advisory Service, J.R. Archer, M.J. Marks
By C.R.W. Spedding, E.C. Diekmahns, Edward Charles Diekmahns, E.C. Dikmahns
By N. W. Pirie