Cambridge University Press,15 Longman,9 Pergamon Press,7 Edward Arnold,5 Prentice Hall,5 Heinemann Educational Books,4 Heinemann,4 Oxford University Press,4 Modern English Publications,4 Macmillan,3 Erlangga,2 George Allen & Unwin,2 Holt, Rinehart and Winston,2 Pergamon Institute of English,1 William Collins Son and Co.,1 Latin American Institute,1 Kent Publishing Company,1 Basil Blackwell,1 D.C. Heath and Company,1 Collins Educational,1