MARKET LEADER BUSINESS ENGLISH PRACTICE FILE UPPER INTERMEDIATE. This book reflects the fast changing world of business with 100% updated material from authentic business sources. Covering topics such as job satisfaction, international marketing and mergers and acquisitions, each unit has a new case study with opinions from successful consultants who work in the real world of business. Ref. number(s): ENG-567 (book) - ENG-223 (audio).