The “Mastery Journal: Master Productivity, Discipline and Focus in 100 Days!” is a hardcover textbook authored by John Lee Dumas, published by Entrepreneuronfire in 2016. It falls under the subject area of Business & Economics and is written in English. Specifically designed for adult education and further education levels, this journal aims to guide readers in achieving mastery over productivity, discipline, and focus within a period of 100 days. With its practical approach and structured format, it is a valuable resource for individuals looking to enhance their skills in these critical areas.