Editing Pope Sixtus IV (section)

==References==
* {{cite book |title=Through Cracks in the Wall: Modern Inquisitions and New Christian 'Letrados' in the Iberian Atlantic World |first=Lúcia Helena |last=Costigan |publisher=Brill |editor-first1=Benjamin |editor-last1=Schmidt |editor-first2=Wim |editor-last2=Klooster |volume=19 |year=2010  }}
* {{cite book |title=The Spanish Inquisition: A Historical Revision |first=Henry |last=Kamen |publisher=Yale University Press   |year=1997  }}
* Vincenzo Pacifici,''Un carme biografico di Sisto IV del 1477'', Società Tiburtina di Storia e d'Arte, Tivoli, 1921 [http://www.societatiburtinastoriaarte.it/STSA-resources/pubblicazioni/misc/Carme_biografico_Sisto_IV.pdf]{{in lang|it}}
* ''"The Historical Encyclopedia of World slavery"'', Editor Junius P. Rodriguez, ABC-CLIO, 1997, {{ISBN|0-87436-885-5}}
* ''"Black Africans in Renaissance Europe"'', Thomas Foster Earle, K. J. P. Lowe, Cambridge University Press, 2005, {{ISBN|0-521-81582-7}}
* ''"Christopher Columbus and the enslavement of the Amerindians in the Caribbean. (Columbus and the New World Order 1492–1992)."'', Sued-Badillo, Jalil, Monthly Review. Monthly Review Foundation, Inc. 1992.
* "''Castile, Portugal, and the Canary Islands: Claims and Counterclaims, 1344–1479"'', Joseph F. O'Callaghan, 1993, pp.&nbsp;287–310, Viator, Volume 24
* "Variations of Popery", Samuel Edgar D.D. Internet Archive, Ebooks and Texts.