There are several books about Disciplined Agile available.
For Senior Leaders
Scott Ambler and Mark Lines, Disciplined Agile Consortium, 2017
This book overviews the Disciplined Agile framework in its entirety – Disciplined Agile Delivery (DAD), Disciplined DevOps, Disciplined Agile IT (DAIT), and Disciplined Agile Enterprise (DAE) – and provides advice for effectively adopting DA strategies within your organization.
A Quick Read
Mark Lines and Scott Ambler, Disciplined Agile Consortium, 2018
This book is a short read that overviews the Disciplined Agile Delivery (DAD) portion of the DA framework. It also works through a case study of a Scrum team that takes it to the next level with DAD, applying DAD to address the myriad of activities that Scrum leaves up to you and then eventually to evolve into a Disciplined DevOps approach.
Making Agile Work in Practice
Scott Ambler and Mark Lines, IBM Press, 2012
This book provides a detailed description of Disciplined Agile Delivery (DAD) from end-to-end. In many ways it is a detailed reference manual in that it describes the advantages and disadvantages of hundreds of agile and lean strategies, and more importantly indicates when and when not to apply them in practice. It’s a big book with a wealth of advice for successfully apply agile in enterprise-class settings.