National Geographic: Mysteries Underground. (2004, November 11). Retrieved December 23, 2024, from http://www.essayworld.com/essays/National-Geographic-Mysteries-Underground/17325
"National Geographic: Mysteries Underground." Essayworld.com. Essayworld.com, 11 Nov. 2004. Web. 23 Dec. 2024. <http://www.essayworld.com/essays/National-Geographic-Mysteries-Underground/17325>
"National Geographic: Mysteries Underground." Essayworld.com. November 11, 2004. Accessed December 23, 2024. http://www.essayworld.com/essays/National-Geographic-Mysteries-Underground/17325.
"National Geographic: Mysteries Underground." Essayworld.com. November 11, 2004. Accessed December 23, 2024. http://www.essayworld.com/essays/National-Geographic-Mysteries-Underground/17325.