All editions of the textbook can be used, although some variation in content

All editions can be used although some content varies between them. 

The Handbook of Global Outsourcing and Offshoring by Ilan Oshri, Julia Kotlarsky and Leslie P. Willcocks. Published by Palgrave Macmillan (link). 3rd Edition (ISBN 9781137437426), 2nd Edition (ISBN 9780230293526) 1st Edition (ISBN 9780230235502).