Agile Manifesto: https://agilemanifesto.org/
Principles behind the Agile Manifesto: https://agilemanifesto.org/principles.html
History of the Agile Manifesto: https://agilemanifesto.org/history.html
Fred Brooks: The Mythical Man-month
Scrum Guide: https://www.scrumguides.org/scrum-guide.html
David J. Anderson: Kanban: Successful Evolutionary Change for Your Technology Business
Atlassian Kanban short video series: https://www.atlassian.com/agile/kanban
Scaled Agile Framework (SAFe): https://www.scaledagileframework.com
Nexus: https://www.scrum.org/resources/online-nexus-guide
Esther Derby and Diana Larsen: Agile Retrospectives: Making Good Teams Great
Simon Sinek, Start with Why: How Great Leaders Inspire Everyone to Take Action
Jeff Sutherland, Scrum: The Art of Doing Twice the Work in Half the Time
General Stanley McChrystal, Team of Teams: New Rules of Engagement for a Complex World
Mike Cohn: Agile Estimation and Planning