Today I heard about The Millionaire Mind by T. Harv Eker. So I searched Google using the following terms: "secrets of the millionaire mind filetype:pdf". Filetype is a search term that we can use to find a specific kind of file.
I also searched for The Mystery of Capital by Hernando De Soto, and I used just the term: "mystery of capital pdf" and got the following results:
I also searched for the Freedom Journal by John Lee Dumas using the terms "freedom journal filetype:pdf" and here's what I got: