<ref>tolerance. Dictionary.com. The American Heritage® Dictionary of the English Language, Fourth Edition. Houghton Mifflin Company, 2004. http://dictionary.reference.com/browse/tolerance (accessed: April 05, 2007).</ref> | <ref>tolerance. Dictionary.com. The American Heritage® Dictionary of the English Language, Fourth Edition. Houghton Mifflin Company, 2004. http://dictionary.reference.com/browse/tolerance (accessed: April 05, 2007).</ref> |