APA Style Citation

Carl Sagan Quotes. (n.d.). BrainyQuote.com. Retrieved June 17, 2019, from BrainyQuote.com Web site: https://www.brainyquote.com/quotes/carl_sagan_841925

Chicago Style Citation

Carl Sagan Quotes. BrainyQuote.com, BrainyMedia Inc, 2019. https://www.brainyquote.com/quotes/carl_sagan_841925, accessed June 17, 2019.

MLA Style Citation

"Carl Sagan Quotes." BrainyQuote.com. BrainyMedia Inc, 2019. 17 June 2019. https://www.brainyquote.com/quotes/carl_sagan_841925