Source reference for the image material
The image material used on this website was either created internally, integrated via Flickr.com and Pixelio.de under ‘Creativ Commons’ or obtained at Fotolia.com. Images created internally are not listed here, because there is not obligation to provide reference for material owned by the publisher!
Images that are licensed via the ‘Creativ Commons’ must only be used according to the same conditions.
Image material created internally or acquired via Fotolia are subject to copyright and must not be copied.