The Master Key System & Your Invisible Power

The Master Key System is a personal development book by Charles F. Haanel (1866-1949) that was originally published as a 24-week correspondence course in 1912. It was later published in book form in 1916 by Psychology Publishing, St. Louis and The Master Key Institute, New York.
Your Invisible Power (1921) by Geneviève Behrend.
Geneviève Behrend (born 1881 in Paris, died 1960 in America) was a French-born author and teacher of Mental Science, a New Thought discipline created by Thomas Troward.