Attendee - Author - Title
Aino Corry - Norm Kerth - Project Retrospectives
Alexander Bartholomäi - Douglas Adams - The Hitch-Hiker's Guide to the Galaxy
Andreas Schliep - Nassim Nicholas Taleb - The Black Swan
Birgit Panzram - Cornelia Funke - Inkheart
Charlotte Malther - Gerald Weinberg - The Secrets of Consulting
Christiane Philips - Kent Beck - Extreme Programming Explained: Embrace Change
Cyril Megard - Adele Faber - How to Talk So Kids Will Listen & Listen So Kids Will Talk
Diana Larsen - Gerald G. Jampolsky - Love Is Letting Go of Fear
Emmanuel Gaillot - CrimethInc - Expect Resistance
Ervin Horvath - Norm Kerth - Project Retrospectives
Esther Derby - George Lakoff - The Political Mind
Francois Bachmann - James P. Carse - Finite and Infinite Games
George Dinwiddie - Ben Ross Berenberg - Churkendoose (Out of print, but I found an audiobook podcast.)
Gitte Klitgaard Hansen - Paulo Coelho - The Alchemist
Ilja Preuß - Jon Jenkins - The 9 Disciplines of a Facilitator
John McFadyen - Ursula K Le Guin - Dispossessed
Josef Scherer - Sam Kaner - Facilitator's Guide to Participatory Decision-Making
Jutta Eckstein - Jeremy Rifkin - The Third Industrial Revolution
Kai Simons - Ken Schwaber - Agile Software Development with Scrum
Karen Greaves - Arbinger Institute - Leadership and Self-Deception
Kerstin Bücher - Marshall B. Rosenberg - Nonviolent Communication
Klaus Schenck - Rosamund Stone Zander, Benjamin Zander - The Art of Possibility
Linda Rising - Timothy D. Wilson - Strangers to Ourselves
Lisbeth Kjellberg - Hans Christian Andersen - Fairy Tales
Marc Bless - Lyssa Adkins - Coaching Agile Teams
Martin Heider - Tony Hsieh - Delivering Happiness
Oana Juncu - Andy Hunt - Pragmatic Thinking and Learning: Refactor Your Wetware
Ralph Miarka - Eva-Maria Zurhorst - Love Yourself, and it Doesn't Matter Who You Marry
Sandra Reupke-Sieroux - Jon Jenkins - The 9 Disciplines of a Facilitator
Sebastian Lang - Stephen Denning - The Leader's Guide to Radical Management
Sebastian Sanitz - Sam Kaner - Facilitator's Guide to Participatory Decision-Making
Simon Roberts - Kent Beck - Extreme Programming Explained: Embrace Change
Thorsten Kalnin - – - Das Handbuch der Musikwirtschaft
Willem Larsen - Christopher Alexander - The Nature of Order
As far as I know, two attendees have not recommended a book during the gathering. Whoever wants to add their recommendation, please do so.