Alistair Cockburn 
Unifying User Stories, Use Cases, Story Maps [EPUB ebook] 
The power of verbs

Use cases, user stories, and story maps have been circling like comets, competing for the same energy of the same people at the same time. There is something obviously similar about all three but just exactly what isn’t obvious. In this ground-breaking book, Dr. Alistair Cockburn, noted expert on all three techniques, co-author of the Agile Manifesto, and author of the definitive work Writing Effective Use Cases, puts them all together, showing how they both complete and complement each other. Cockburn starts by attending to the seven key concepts without which none of them can be written well, and with mastery of which you can move freely between them. From there he breaks down user stories, then use cases, then story maps one by one, in clear and practical terms. Finally, he shows how to move between them, making them more effective in combination. The book contains exercises and drills, making it suitable for self study and classroom teaching.