Viljoen, Dr. Rica books & textbook
Spiral Dynamics in Action: Humanity's Master Code
Beck, Prof. Don Edward Hebo Larsen, Teddy Solonin, Sergey Viljoen, Dr. Rica Johns, Thomas Q.
Wiley /2018-05-29 Paperback / 296 Pages
isbn-10: 1119387183 / isbn-13: 9781119387183