Mark Harrison has been an ELT author for 20 years. He has written a range of titles mainly in the areas of grammar and testing. In the grammar field he has authored or co-authored titles in the Oxford Living Grammar, Grammar Spectrum and Oxford Practice Grammar series for OUP. He has also written numerous practice tests books for the Cambridge ESOL exams and a Use of English Skills book, for OUP and Macmillan. In recent years, he has also worked extensively on the Macmillan English Campus, writing and devising online materials, as well as writing other online and CD-ROM materials. Vanessa Jakeman has co-ordinated English Language and EAP programmes and worked extensively in the field of English Language Testing, in the UK and overseas. She has a range of jointly-authored ELT publications which comprise Cambridge ESOL Practice Test books and course books for the International English Language Testing System (IELTS). Ken Paterson is currently a freelance writer, having finished a twenty-year career at the University of Westminster, UK, as Director of the Centre for English Learning and Teaching. Ken has been involved in pedagogical grammar since the early 1990s, writing a number of grammar practice books for Oxford University Press and DELTA.