Animation of Nitrogen Cycle
   Presents an active diagram of this process, together with a description of each stage and component.
   http://www.sp.uconn.edu/~terry/229sp03/lectures/Ncycleanim.html

Nitrogen Cycle
   Diagram, facts, nitrogen fixation methods, and what fixes nitrogen.
   http://homepages.nyu.edu/~pet205/nitrogen.html

Nutrient Overload: Unbalancing the Global Nitrogen Cycle
   Shows how nutrient pollution through man can lead to algae blooms that unbalance the cycle.
   http://pubs.wri.org/pubs_content_text.cfm?ContentID=1412

Streams Reduce Nitrogen Pollution, Scientists Find
   Article describing the finding of scientists that small streams are extremely efficient at removing some of the excess nitrogen that is flowing into waterways, endangering fish and other forms of aquatic life.
   http://news.nationalgeographic.com/news/2001/05/0504_smallstreams.html

The Microbial World: The Nitrogen Cycle and Nitrogen Fixation
   How nitrogen gets "fixed" by bacteria to become available for plants on earth.
   http://www.biology.ed.ac.uk/research/groups/jdeacon/microbes/nitrogen.htm

The Nitrogen Cycle
   Diagram and explanation of the cycle.
   http://www.physicalgeography.net/fundamentals/9s.html