World Book — Columbus, Christopher (Archive.is saytida 2012-12-03 sanasida arxivlangan) „Columbus, Christopher“. World Book Store has the encyclopedia, dictionary, atlas, homework help, study aids, and curriculum guides. 2010
britannica.com
Christopher Columbus Encyclopædia Britannica. 2010. Encyclopædia Britannica Online. 8-iyun 2010-yil.
google.co.uk
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Hoxie, Frederic {{subst:FULLPAGENAME}} Encyclopedia of North American Indians Houghton Mifflin (March 1997) ISBN 978-0-395-66921-1 p.568 [1][sayt ishlamaydi][sayt ishlamaydi]
Herbst, Philip The Color of Words: An Encyclopaedic Dictionary of Ethnic Bias in the United States Intercultural Press Inc (31-dekabr 1997-yil) ISBN 978-1-877864-97-1 p.116 [2]
Wilton, David; Brunetti, Ivan Word myths: debunking linguistic urban legends Oxford University Press USA (13-yanvar 2005-yil) ISBN 978-0-19-517284-3 pp. 164-165 [3]
World Book — Columbus, Christopher (Archive.is saytida 2012-12-03 sanasida arxivlangan) „Columbus, Christopher“. World Book Store has the encyclopedia, dictionary, atlas, homework help, study aids, and curriculum guides. 2010