By Agusti Reventos Tarrida
By Francoise Dal'Bo
By Clara Loeh
By Liviu I. Nicolaescu
By Boris Makarov, Anatolii Podkorytov
By Catriona Maclean, Daniel Perrin
By Blinko, Janine, Graham, Noel
By G. N. Watson
By Trorsky, Maruda
By Nicolaides, A.
By Ladybird, Land, Fiona
By Brannan, David A
By Roe, John
By Giblin, P.
By Aichele, Douglas B, Hopfensperger, Patrick W, Leiva, Miriam A, Mason, Marguerite M, Murphy, Stuart J, Schell, Vicki J
By Manhattan GMAT Prep, Prep Mg, Manhattan Gre
By Blyton, Enid, Chorion CGI
By Richards, Steve
By Mortenson, Michael E.
By Doebner, Heinz-Dietrich, Hennig, Jörg-Dieter
By Field, Robert
By Neumann, Peter M.
By Farin, Gerald
By Room, T. G.
By O'Rourke, Joseph
By MU120 Course Team
By Hill, Eric
By Lewis, Anna, etc.
By Jenkins, Gerald
By Repka, Joe