United States accuses Soviets of using poison gas. (2013). The History Channel website. Retrieved 12:09, May 18, 2013, from http://www.history.com/this-day-in-history/united-states-accuses-soviets-of-using-poison-gas.
United States accuses Soviets of using poison gas. [Internet]. 2013. The History Channel website. Available from: http://www.history.com/this-day-in-history/united-states-accuses-soviets-of-using-poison-gas [Accessed 18 May 2013].
“United States accuses Soviets of using poison gas.” 2013. The History Channel website. May 18 2013, 12:09 http://www.history.com/this-day-in-history/united-states-accuses-soviets-of-using-poison-gas.
“United States accuses Soviets of using poison gas,” The History Channel website, 2013, http://www.history.com/this-day-in-history/united-states-accuses-soviets-of-using-poison-gas [accessed May 18, 2013].
“United States accuses Soviets of using poison gas,” The History Channel website, http://www.history.com/this-day-in-history/united-states-accuses-soviets-of-using-poison-gas (accessed May 18, 2013).
United States accuses Soviets of using poison gas [Internet]. The History Channel website; 2013 [cited 2013 May 18] Available from: http://www.history.com/this-day-in-history/united-states-accuses-soviets-of-using-poison-gas.
United States accuses Soviets of using poison gas, http://www.history.com/this-day-in-history/united-states-accuses-soviets-of-using-poison-gas (last visited May 18, 2013).
United States accuses Soviets of using poison gas. The History Channel website. 2013. Available at: http://www.history.com/this-day-in-history/united-states-accuses-soviets-of-using-poison-gas. Accessed May 18, 2013.