http://2createawebsite.com/build/html.html

http://office.microsoft.com/en-us/excel/default.aspx

http://www.free-training-tutorial.com/

http://www.techsupportforum.com/microsoft-support/microsoft-office-support/164607-exel-filter-2007-a.html

http://www.homeandlearn.co.uk/excel2007/Excel2007.html

http://www.researchandmarkets.com/reports/596897