By Walker, Mary
By Evans, Lynette
By Lawrence, Lynne
By Tompkins, Jane P.
By Littau, Karin
By Grimaud, Michel, Pilorget, Bruno
By Awdry, Reverend Wilbert Vere
By Goodman, Burton
By Collins Easy Learning
By Foreman, Michael
By Boscher, Paul
By Lingo Mastery
By Bernard, Fred
By Guirao-Julien, Magdalena
By Hulme, Charles, Joshi, R. Malatesha
By Collins GCSE
By Blake, Ruth, Cooper, Alison, Roles, Sue, Whitaker, Debbie
By Chatfield, Tom
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By Rogers, Bruce, Kenny, Nick
By Huizenga, Jann
By Lane, Sarah
By Shipton, Paul, Collins Big Cat, Moon, Cliff
By JENNY GILES
By Baker, Catherine, Corke, Estelle, Collins Big Cat
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By David J Newman (National Institutes of Health USA)