Lebensfreude - Was uns wirklich glücklich machtMartin Schott, Mehmet Yesilgöz, Beate Kollewe, Gerd Harms, Emil Knies, Susanne Barknowitz, Cornelia Peukert, Susan Nitzschmann, Renate Kirstein, Karin Margarete Hill · First published 2010Open the Tome
