Soil Science Department, Faculty of Agriculture, Cairo University, Giza, Egypt (email)
http://www.iuss.org/19th%20WCSS/Symposium/pdf/0616.pdf
http://www.iuss.org/19th%20WCSS/Symposium/pdf/0382.pdf
http://www.iuss.org/index.php?option=com_content&view=article&id=13&Itemid=21