First Adopt-a-Highway sign goes up. (2013). The History Channel website. Retrieved 8:22, May 21, 2013, from http://www.history.com/this-day-in-history/first-adopt-a-highway-sign-goes-up.
First Adopt-a-Highway sign goes up. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/first-adopt-a-highway-sign-goes-up [Accessed 21 May 2013].
“First Adopt-a-Highway sign goes up.” 2013. The History Channel website. May 21 2013, 8:22 http://www.history.com/this-day-in-history/first-adopt-a-highway-sign-goes-up.
“First Adopt-a-Highway sign goes up,” The History Channel website, 2013, http://www.history.com/this-day-in-history/first-adopt-a-highway-sign-goes-up [accessed May 21, 2013].
“First Adopt-a-Highway sign goes up,” The History Channel website, http://www.history.com/this-day-in-history/first-adopt-a-highway-sign-goes-up (accessed May 21, 2013).
First Adopt-a-Highway sign goes up [Internet]. The History Channel website; 2013 [cited 2013 May 21] Available from: http://www.history.com/this-day-in-history/first-adopt-a-highway-sign-goes-up.
First Adopt-a-Highway sign goes up, http://www.history.com/this-day-in-history/first-adopt-a-highway-sign-goes-up (last visited May 21, 2013).
First Adopt-a-Highway sign goes up. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/first-adopt-a-highway-sign-goes-up. Accessed May 21, 2013.