By Radislav A. Potyrailo, Wilhelm F. Maier
By Ben Derudder, Jonathan V. Beaverstock, Frank Witlox
By Dorothy Merritts, etc., Andrew deWet (Franklin Marshall College, USA), Kirsten Menking (Vassar College
By Brian Doherty, Marius de Geus
By G. Miller (President, Earth Education and Research)
By A. J. Parsons, P.G. Knight
By John McCarthy
By Robert T. Watson, Marufu C. Zinyowera, Richard H. Moss
By Mike Tooley (Brooklands College, UK), Lloyd Dingle
By Manfred Binder, Martin Janicke, Ulrich Petschow
By Rudiger Wurzel, James Connelly (University of Hull, UK)
By Jennifer Elliott