Bob first described the Diamond Model (and the features of action) in his first book: For Whites Only. In his next book, Authentic Leadership: Courage in Action he developed the "features of action" further which then became the Action Wheel. His book 7 Zones for Leadership continued the development of his action/authentic leadership theories.
The Action Wheel is still the basis of all the work we do and is descibed at length on the pages of this site.
Feel free to use the contact page here if you want more info.