I am selling these items as they have been stored unused since purchase. Side by Side 2 Side by Side 3 Side by Side 4 A set of 4 books. A set of textbooks and workbooks for English language learning. - Series Name: SIDE by SIDE Extra - Type: Textbook - Author: Steven J. Molinsky, Bill Bliss - Publisher: PEARSON - Contents: English language learning workbook - Volumes: Book 3 & Book 4 - International Edition: International Edition Thank you for looking.