Robert Ingersoll was an American politician and orator best known as "the great agnostic" who popularized criticism of the Bible and scientific rationalism.
Robert Green Ingersoll. (2013). The Biography Channel website. Retrieved 04:30, Jun 19, 2013, from http://www.biography.com/people/robert-ingersoll-9349321.
Robert Green Ingersoll. [Internet]. 2013. The Biography Channel website. Available from: http://www.biography.com/people/robert-ingersoll-9349321 [Accessed 19 Jun 2013].
"Robert Green Ingersoll." 2013. The Biography Channel website. Jun 19 2013, 04:30 http://www.biography.com/people/robert-ingersoll-9349321.
"Robert Green Ingersoll," The Biography Channel website, 2013, http://www.biography.com/people/robert-ingersoll-9349321 [accessed Jun 19, 2013].
"Robert Green Ingersoll," The Biography Channel website, http://www.biography.com/people/robert-ingersoll-9349321 (accessed Jun 19, 2013).
Robert Green Ingersoll [Internet]. The Biography Channel website; 2013 [cited 2013 Jun 19] Available from: http://www.biography.com/people/robert-ingersoll-9349321.
Robert Green Ingersoll, http://www.biography.com/people/robert-ingersoll-9349321 (last visited Jun 19, 2013).
Robert Green Ingersoll. The Biography Channel website. 2013. Available at: http://www.biography.com/people/robert-ingersoll-9349321. Accessed Jun 19, 2013.