By Friedrich Ruttner, Eric Milner, John E. Dews
By Duncan G. Steel
By Glenys Roberts
By Joseph E. Stiglitz, Mary Kaldor
By L.S. Cobley, W.M. Steele
By L.O. Roth, etc., H.L. Field (Oklahoma State University, USA)
By Derek G.W. Soper
By R. B. H. Wills, W.B. McGlasson, Douglas Graham, T.H. Less, E.G. Hall
By Herbert Edward Street
By A. A. Hanson (Silver Spring, MD)
By J.M.S.De Pury
By Alfred Max Mayer, Alexandra Poljakoff-Mayber
By H.J. Wilms, et al
By Jones, Gareth
By Food and Agriculture Organization of the United Nations
By M. E. Adams
By J.M. Hodgson, etc.
By Peter Fraenkel
By N.T. Gill, K.C. Vear
By Cooke, George William
By Dupriez, Hugues, Leener, Philippe De, de Leener, Philippe
By J. Andrews
By Donald R. Field, G. E. Wickens, J. R. Goodin
By John Bartholomew and Son
By S.S. Johl
By Porritt, Jonathon