Mcniell, J. R. "5.1 The Columbian Exchange." The Columbian Exchange. N.p., 22 June 2008. Web. 19 May 2015.
Newson, Linda. "Ecological Impacts of European Colonizations in the Americas." Encyclopedia of Western Colonialism since 1450. Ed. Thomas Benjamin. Vol. 1. Detroit: Macmillan Reference USA, 2007. 330-336. Global Issues In Context. Web. 12 May 2015.
"Transcript: Physical and Cultural Exchange." American History. ABC-CLIO, 2015. Web. 14 May 2015.
Crosby, Alfred W. "Alfred W. Crosby on the Columbian Exchange."Smithsonian. N.p., n.d. Web. 14 May 2015
Newson, Linda. "Ecological Impacts of European Colonizations in the Americas." Encyclopedia of Western Colonialism since 1450. Ed. Thomas Benjamin. Vol. 1. Detroit: Macmillan Reference USA, 2007. 330-336. Global Issues In Context. Web. 12 May 2015.
"Transcript: Physical and Cultural Exchange." American History. ABC-CLIO, 2015. Web. 14 May 2015.
Crosby, Alfred W. "Alfred W. Crosby on the Columbian Exchange."Smithsonian. N.p., n.d. Web. 14 May 2015