Martin H. Manser has been a professional reference-book editor since 1980. He has worked on over 150 reference books with a contemporary appeal. His English-language reference titles include the Oxford Learner's Pocket Dictionary, the Penguin Wordmaster Dictionary, the Bloomsbury Good Word Guide, Chambers Thesaurus, the Macmillan Student's Dictionary, the Facts on File Visual Dictionary, and the Guinness Book of Words. He has more recently compiled and edited books on writing: the Penguin Writer's Manual, The Facts on File Guide to Style, The Facts on File Guide to Good Writing. He also leads courses at companies and organizations to help users of English write clear documents.