How The States Got Their Shapes: The Great Plains, Trains . (2013). The History Channel website. Retrieved 4:58, May 19, 2013, from http://www.history.com/shows/how-the-states-got-their-shapes/videos/playlists/.
How The States Got Their Shapes: The Great Plains, Trains . [Internet]. 2013. The History Channel website. Available from: http://www.history.com/shows/how-the-states-got-their-shapes/videos/playlists/ [Accessed 19 May 2013].
“How The States Got Their Shapes: The Great Plains, Trains .” 2013. The History Channel website. May 19 2013, 4:58 http://www.history.com/shows/how-the-states-got-their-shapes/videos/playlists/.
“How The States Got Their Shapes: The Great Plains, Trains ,” The History Channel website, 2013, http://www.history.com/shows/how-the-states-got-their-shapes/videos/playlists/ [accessed May 19, 2013].
“How The States Got Their Shapes: The Great Plains, Trains ,” The History Channel website, http://www.history.com/shows/how-the-states-got-their-shapes/videos/playlists/ (accessed May 19, 2013).
How The States Got Their Shapes: The Great Plains, Trains [Internet]. The History Channel website; 2013 [cited 2013 May 19] Available from: http://www.history.com/shows/how-the-states-got-their-shapes/videos/playlists/.
How The States Got Their Shapes: The Great Plains, Trains , http://www.history.com/shows/how-the-states-got-their-shapes/videos/playlists/ (last visited May 19, 2013).
How The States Got Their Shapes: The Great Plains, Trains . The History Channel website. 2013. Available at: http://www.history.com/shows/how-the-states-got-their-shapes/videos/playlists/. Accessed May 19, 2013.