Inner Game is a 9-book series first released in 1974 with contributions by W. Timothy Gallwey, Alexandre Sanches Camacho, and Barry Green.
1974 • 1 Reader • 188 pages
1986 • 2 Readers • 272 pages • 4.3
1986 • 4 Readers • 257 pages • 3.5
1974 • 1 Reader • 132 pages