http://en.wikipedia.org/wiki/Invisible_hand
http://plus.maths.org/issue14/features/smith/
http://www.investorwords.com/2633/invisible_hand.html
http://adamsmithslostlegacy.blogspot.com/2007/12/invisible-hand-no-357.html
http://tw.epochtimes.com/011/1310.htm
http://www.answers.com/topic/invisible-hand#Dictionary_d
http://en.wikipedia.org/wiki/Adam_Smith
http://www.bibliomania.com/2/1/65/112/frameset.html
http://en.wikipedia.org/wiki/The_Wealth_of_Nations