American physicist Robert H. Goddard built the world's first liquid-fueld rocket in 1926 and is best known as the founding father of modern rocketry.
Robert Hutchings Goddard. (2013). The Biography Channel website. Retrieved 03:06, May 25, 2013, from http://www.biography.com/people/robert-goddard-9313695.
Robert Hutchings Goddard. [Internet]. 2013. The Biography Channel website. Available from: http://www.biography.com/people/robert-goddard-9313695 [Accessed 25 May 2013].
"Robert Hutchings Goddard." 2013. The Biography Channel website. May 25 2013, 03:06 http://www.biography.com/people/robert-goddard-9313695.
"Robert Hutchings Goddard," The Biography Channel website, 2013, http://www.biography.com/people/robert-goddard-9313695 [accessed May 25, 2013].
"Robert Hutchings Goddard," The Biography Channel website, http://www.biography.com/people/robert-goddard-9313695 (accessed May 25, 2013).
Robert Hutchings Goddard [Internet]. The Biography Channel website; 2013 [cited 2013 May 25] Available from: http://www.biography.com/people/robert-goddard-9313695.
Robert Hutchings Goddard, http://www.biography.com/people/robert-goddard-9313695 (last visited May 25, 2013).
Robert Hutchings Goddard. The Biography Channel website. 2013. Available at: http://www.biography.com/people/robert-goddard-9313695. Accessed May 25, 2013.