Schwarz-weiß-Foto
CC BY Charlotte Astrid 2.0
Farbfoto einer gefüllten Kaffeetasse mit Schnurrbart
CC BY coffee_circle 2.0
Farbfoto
CC BY wissenschaftsjahr 2.0)
http://creativecommons.org/licenses/by/2.0/deed.de
Farbfoto
CC BY Rusty Clark 2.0
http://creativecommons.org/licenses/by/2.0/deed.de
Farbfoto
CC BY eutrophication & hypoxia 2.0
http://creativecommons.org/licenses/by/2.0/
Automobiles release nitrogen oxides (NOx) into the atmosphere and can be a significant source on nitrogen pollution to coastal areas
Farbfoto
CC BY Presse Nordelbien 2.0
http://creativecommons.org/licenses/by/2.0/
Farbfoto
CC BY Chris eisenbahner 2.0
http://creativecommons.org/licenses/by/2.0/deed.de