Sagan. (2004, May 5). Retrieved October 2, 2025, from http://www.essayworld.com/essays/Sagan/7341
"Sagan." Essayworld.com. Essayworld.com, 5 May. 2004. Web. 2 Oct. 2025. <http://www.essayworld.com/essays/Sagan/7341>
"Sagan." Essayworld.com. May 5, 2004. Accessed October 2, 2025. http://www.essayworld.com/essays/Sagan/7341.
"Sagan." Essayworld.com. May 5, 2004. Accessed October 2, 2025. http://www.essayworld.com/essays/Sagan/7341.