HBR's Must-Reads on Leadership: What Makes a Leader?
Daniel Coleman
Testing in Scrum
Tilo Linz
Coaching, Mentoring, and Managing: A Coach Guidebook
Micki Holliday
Mission Control
Michael Sölter & Hannes S. Griebel & Martina Albrecht
Scrum Mastery (Geoff Watts' Agile Mastery Series)
Geoff Watts
Liminal Thinking: Create the Change You Want by Changing the ...
Dave Gray