Eckard, R.(2014) Factors Affecting Nitrate Accumulating in Herbage . Retrieved from

http://www.greenhouse.unimelb.edu.au/nitrogen/Nitrate.htm

ESSRE.(2001) General Discription of the ESSRE Survey Sites. Retrieved from

http://essre.rpcs.org/ESSRELocations.htm

Hilton J. (2014) Comprehensive Description. Retrieved from

http://eol.org/pages/1114464/details

Laria G., Shay M. & Kuser M. (2014) Influences on Nitrate Leaching in the Soils of an Ecosystem

Deciduous  Forest; A Case Study, 1-15.

Murphy, S. (2007) General Information of Nitrogen. City of Boulder/ USGS Water Quality Monitoring.

http://bcn.boulder.co.us/basin/data/NEW/info/NO3+NO2.html  

Oram, B.(2014) Iron and Maganese in Water A Common Problem in Northeast Pennsylvania.

http://www.water-research.net/index.php/iron

Poaceae. (2014) In Encyclopedia Britannica. Retrieved from

http://www.britannica.com/EBchecked/topic/465603/Poaceae

Serchan S.& Jones D. (2009)The Baltimore Ecosystem Study Virtual Tour.

http://www.beslter.org/virtual_tour/Nitrate.html