Cities of the Underworld: A-Bomb Underground. (2013). The History Channel website. Retrieved 11:19, June 18, 2013, from http://www.history.com/videos/cities-of-the-underworld-a-bomb-underground.
Cities of the Underworld: A-Bomb Underground. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/videos/cities-of-the-underworld-a-bomb-underground [Accessed 18 Jun 2013].
“Cities of the Underworld: A-Bomb Underground.” 2013. The History Channel website. Jun 18 2013, 11:19 http://www.history.com/videos/cities-of-the-underworld-a-bomb-underground.
“Cities of the Underworld: A-Bomb Underground,” The History Channel website, 2013, http://www.history.com/videos/cities-of-the-underworld-a-bomb-underground [accessed Jun 18, 2013].
“Cities of the Underworld: A-Bomb Underground,” The History Channel website, http://www.history.com/videos/cities-of-the-underworld-a-bomb-underground (accessed Jun 18, 2013).
Cities of the Underworld: A-Bomb Underground [Internet]. The History Channel website; 2013 [cited 2013 Jun 18] Available from: http://www.history.com/videos/cities-of-the-underworld-a-bomb-underground.
Cities of the Underworld: A-Bomb Underground, http://www.history.com/videos/cities-of-the-underworld-a-bomb-underground (last visited Jun 18, 2013).
Cities of the Underworld: A-Bomb Underground. The History Channel website. 2013. Available at: http://www.history.com/videos/cities-of-the-underworld-a-bomb-underground. Accessed Jun 18, 2013.