3 books in series

inner Game

inner Game is a 3-book series with 3 released primary works first released in 1974 with contributions by W. Timothy Gallwey, Edd Hanzelik, and John Horton.

The Inner Game of Tennis: The Classic Guide to the Mental Side of Peak Performance
The Inner Game of Stress: Outsmart Life's Challenges and Fulfill Your Potential
The Inner Game of Work