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.