Farbgrafik
(CC BY-Jörg Rittmeister SA 3.0
http://creativecommons.org/licenses/by-sa/3.0/deed.en
Farbgrafik
CC BY-JHeuser / Dake / Wapcaplet SA 2.5
http://creativecommons.org/licenses/by-sa/2.5/deed.en
Farbgrafik
(CC BY-Jörg Rittmeister SA 3.0
http://creativecommons.org/licenses/by-sa/3.0/deed.en
Farbgrafik
CC BY-JHeuser / Dake / Wapcaplet SA 2.5
http://creativecommons.org/licenses/by-sa/2.5/deed.en
Farbgrafik
CC BY-A-kreislauf01.jpg: Jörg Rittmeister
derivative work: Vezixig
SA 2.5
http://creativecommons.org/licenses/by-sa/2.5/deed.de