Quellenverzeichnis Illustrationen: Bettina Kumpe, Braunschweig S. 32: 1 © Thinkstock/iStock/gpointstudio; 2 © iStock/andresr; 3 © fotolia/Alexander Rochau; 4 © iStock/M_a_y_a; 5 © Thinkstock/iStock/ariwasabi; 6 © Thinkstock/Fuse; 7 © iStock/MorePixels; 8 © Thinkstock/iStock/monkeybusinessimages; 9 © Thinkstock/iStock/targovcom S. 34: von links © iStock/jhorrocks; © iStock/jacomstephens; © Thinkstock/iStock/dmbaker S. 35: links © Thinkstock/iStock/Wavebreakmedia; rechts © iStock/pixdeluxe S. 37: © Thinkstock/iStock/Jacob Wackerhausen S. 38: Würfel © Thinkstock/Wavebreakmedia Ltd Javisst! aktuell A1, ISBN 978-3-19-105405-2, © Hueber Verlag