Arthur Walker found guilty of spying for Soviet Union. (2013). The History Channel website. Retrieved 1:31, May 26, 2013, from http://www.history.com/this-day-in-history/arthur-walker-found-guilty-of-spying-for-soviet-union.
Arthur Walker found guilty of spying for Soviet Union. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/arthur-walker-found-guilty-of-spying-for-soviet-union [Accessed 26 May 2013].
“Arthur Walker found guilty of spying for Soviet Union.” 2013. The History Channel website. May 26 2013, 1:31 http://www.history.com/this-day-in-history/arthur-walker-found-guilty-of-spying-for-soviet-union.
“Arthur Walker found guilty of spying for Soviet Union,” The History Channel website, 2013, http://www.history.com/this-day-in-history/arthur-walker-found-guilty-of-spying-for-soviet-union [accessed May 26, 2013].
“Arthur Walker found guilty of spying for Soviet Union,” The History Channel website, http://www.history.com/this-day-in-history/arthur-walker-found-guilty-of-spying-for-soviet-union (accessed May 26, 2013).
Arthur Walker found guilty of spying for Soviet Union [Internet]. The History Channel website; 2013 [cited 2013 May 26] Available from: http://www.history.com/this-day-in-history/arthur-walker-found-guilty-of-spying-for-soviet-union.
Arthur Walker found guilty of spying for Soviet Union, http://www.history.com/this-day-in-history/arthur-walker-found-guilty-of-spying-for-soviet-union (last visited May 26, 2013).
Arthur Walker found guilty of spying for Soviet Union. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/arthur-walker-found-guilty-of-spying-for-soviet-union. Accessed May 26, 2013.