APA Style Citation

Carl Sagan Quotes. (n.d.). BrainyQuote.com. Retrieved July 18, 2019, from BrainyQuote.com Web site: https://www.brainyquote.com/quotes/carl_sagan_841914

Chicago Style Citation

Carl Sagan Quotes. BrainyQuote.com, BrainyMedia Inc, 2019. https://www.brainyquote.com/quotes/carl_sagan_841914, accessed July 18, 2019.

MLA Style Citation

"Carl Sagan Quotes." BrainyQuote.com. BrainyMedia Inc, 2019. 18 July 2019. https://www.brainyquote.com/quotes/carl_sagan_841914