https://eo.ucar.edu/kids/green/cycles6.htm [2]
http://en.wikipedia.org/wiki/Carbon_cycle [3]
http://teeic.indianaffairs.gov/er/carbon/carboninfo/cycle/ [4]
Links[1] https://www.hootsgo.org/?q=node/6327 [2] https://eo.ucar.edu/kids/green/cycles6.htm [3] http://en.wikipedia.org/wiki/Carbon_cycle [4] http://teeic.indianaffairs.gov/er/carbon/carboninfo/cycle/
