By Sherman K. Stein, Anthony Barcellos
By Open University Course Team
By Frank Ayres, Elliott Mendelson
By Eastaway, Rob, Rob Eastaway, Jeremy Wyndham
By D C Spencer, David V. Widder
By Collins GCSE
By Sherman K. Stein
By K. F. Riley (University of Cambridge), M. P. Hobson (University of Cambridge), S. J. Bence
By Mark Rowland, Rowland, Mark
By Ross L. Finney, George B. Thomas
By Dominic Welsh (Fellow and Tutor in Mathematics, Fellow and Tutor in Mathematics, Merton College, Oxford)
By Tom Apostol
By M. J. D. Powell
By D.W. Jordan, Peter Smith
By Michael C. Reed (Duke University)
By Thomas B. A. Senior
By Paul Fannon, Vesna Kadelburg, Ben Woolley, Stephen Ward
By Karen Pao, Frederick Soon
By Jerrold Marsden, Anthony Tromba
By School Mathematics Project
By John Kruschke (Indiana University, Bloomington, USA)
By Rachel Riley, Dr Gareth Moore
By Richard L. Burden, J. Douglas Faires
By Mihajlo D. Mesarovic, etc.
By W. Michael Kelley