BIBLIOGRAPHY            BIBLIOGRAPHY           BIBLIOGRAPHY

Encyclopedia Americana.(2011). Potassium.  Grolier Online :     

http://ea.grolier.com/article?id=0319900-00

Erickson, L., Fuhrmann, M.(2011, July 26). Soil Remediation.  Access Science:

http://www.accessscience.com

Globe. (1997). Quantitative Land Cover Sample Site Protocol. Retrived from:

 http://globe.gov/sda/tg/landcover/Quantitative.pdf

McAfee, J.  (2008). Potassium, A Key Nutrient for Plant Growth. Department of Soil and

Crop Sciences: http://jimmcafee.tamu.edu/files/potassium%20a%20key%20nutrient%20for%20plant%20growth.pdf

Rehm, G. , Schmitt, M. (2011). Potassium for Crop Production.  University of Minesota:

http://www.extension.umn.edu/distribution/cropsystems/dc6794.html