http://people.howstuffworks.com/6-of-the-worlds-greatest-missing-treasures.htm#page=5
http://listverse.com/2013/02/07/10-mysterious-lost-treasures-of-the-world/
http://www.britainexplorer.com/top-ten-lost-treasures.html
http://guardianlv.com/2013/10/8-priceless-treasures-that-are-still-undiscovered/
http://www.mandatory.com/2013/04/18/10-lost-treasures-that-people-are-still-trying-to-find/10
http://mentalfloss.com/article/31394/10-lost-treasures-could-make-you-very-rich
http://en.wikipedia.org/wiki/List_of_missing_treasure