Three Things You Didn't Know About: Vacuums. (2013). The History Channel website. Retrieved 10:15, June 19, 2013, from http://www.history.com/shows/modern-marvels/videos/playlists/three-things-you-didnt-know-about.
Three Things You Didn't Know About: Vacuums. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/shows/modern-marvels/videos/playlists/three-things-you-didnt-know-about [Accessed 19 Jun 2013].
“Three Things You Didn't Know About: Vacuums.” 2013. The History Channel website. Jun 19 2013, 10:15 http://www.history.com/shows/modern-marvels/videos/playlists/three-things-you-didnt-know-about.
“Three Things You Didn't Know About: Vacuums,” The History Channel website, 2013, http://www.history.com/shows/modern-marvels/videos/playlists/three-things-you-didnt-know-about [accessed Jun 19, 2013].
“Three Things You Didn't Know About: Vacuums,” The History Channel website, http://www.history.com/shows/modern-marvels/videos/playlists/three-things-you-didnt-know-about (accessed Jun 19, 2013).
Three Things You Didn't Know About: Vacuums [Internet]. The History Channel website; 2013 [cited 2013 Jun 19] Available from: http://www.history.com/shows/modern-marvels/videos/playlists/three-things-you-didnt-know-about.
Three Things You Didn't Know About: Vacuums, http://www.history.com/shows/modern-marvels/videos/playlists/three-things-you-didnt-know-about (last visited Jun 19, 2013).
Three Things You Didn't Know About: Vacuums. The History Channel website. 2013. Available at: http://www.history.com/shows/modern-marvels/videos/playlists/three-things-you-didnt-know-about. Accessed Jun 19, 2013.