Sky is the Limit: The Art of of Upgrading Your Life
Dale Carnegie, Abner Bayley, P. T. Barnum, Marcus Aurelius, Henry Thomas Hamblin, Joseph Murphy, William Crosbie Hunter, Ralph Waldo Emerson, Henry H. Brown, Russell H. Conwell, William Atkinson, Benjamin Franklin, B. F. Austin, H. A. Lewis, L. W. Rogers, Douglas Fairbanks, Sun Tzu, Samuel Smiles, Charles F. Haanel, Florence Scovel Shinn, Wallace D. Wattles, James Allen, Lao Tzu, Khalil Gibran, Orison Swett Marden