Here's the link for the Paperback:
https://www.amazon.com/Gateway-Pierre-M-Drolet/dp/1480807109/ref=tmm_pap_swatch_0?_encoding=UTF8&qid=&sr=
Link for Kindle edition:
https://www.amazon.com/Gateway-Pierre-M-Drolet-ebook/dp/B07947XNJD/ref=tmm_kin_swatch_0?_encoding=UTF8&qid=&sr=