Source: https://www.amazon.com/Mastery-Journal-mastering-productivity-discipline/dp/0996234012/ref=as_li_ss_tl?ie=UTF8&qid=1495598018&sr=8-1&keywords=mastery+journal&linkCode=sl1&tag=mone078-20&linkId=57007b0598dd6df75c83ecdab7b3d03c