Jennifer Speake and Mark LaFlaur. "Thule." The Oxford Essential Dictionary of Foreign Terms in English. 1999. Encyclopedia.com. 26 Dec. 2009 <http://www.encyclopedia.com>.
Jennifer Speake and Mark LaFlaur. "Thule." The Oxford Essential Dictionary of Foreign Terms in English. 1999. Encyclopedia.com. (December 26, 2009). http://www.encyclopedia.com/doc/1O33-Thule.html
Jennifer Speake and Mark LaFlaur. "Thule." The Oxford Essential Dictionary of Foreign Terms in English. 1999. Retrieved December 26, 2009 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O33-Thule.html