Sources for pictures

Fotolia.com

Oscar Brunet, Harry Macias, PhotoSG, Piligrim, Olga Popova, Bernd S., Gina Sanders, Tom, W. Zikas

istockphoto.com

Jaimie Duplass, Murat Giray Kaya, Günay Mutlu, Oleg Prikhodko

portamagica.de

Antje Hertel

Further Sources

Own pictures of ACS Informatik GmbH