Following are the websites that support the research of "The Cardinals of the Holy Roman Church".

• Annuario pontificio per l'anno 1863; 1865; 1866; 1867; 1868; 1869; and 1870.

• Apostolic Succession in the Roman Catholic Church, created by Mr. Charles N. Bransom, Jr., director and editor of Revue des Ordinations Épiscopales.

• Beni Ecclesiastici in Web, Segretaria Generale della Conferenza Episcopale Italiana, Ufficio Nazionale per i Beni Culturali Ecclesiastici e Servizio Informatico.

• Bildarchiv Austria. Die Bildplattform der Österreichischen Nationalbibliothek.

• The Catholic Encyclopedia.

• Encyclopædia Britannica.

• The Hierarchy of the Catholic Church. Current and historical information about its bishops and dioceses

• Katolische Bischöfe in China, in English, created by Mr. Andreas Brender, M.A..

• CHRACAS. Diario Ordinario (DI ROMA). SUNTO DI NOTIZIE E INDICI. Vol. I (1718 - 1736).

• Dictionnaire d'histoire et de géographie ecclésiastiques - Alfred Baudrillart
  Volume 5; Volume 6; Volume 7; Volume 8;Volume 9; Volume 13; and Volume 14.

• Epitome Pontificum Romanorum a S. Petro usque ad Paulum IIII : gestorum (videlicet) electionisque singulorum, & conclauium compendiaria narratio : cardinalium item nomina, dignitatum tituli, insignia legationes, patria & obitus.

• Fondazione Marco Besso, Rome.

• Genealogie Mittelalter. Mittelalterliche Genealogie im Deutschen Reich bis zum Ende der Staufer.

• GENEALOGY.EU. Genealogy page with royal and noble family trees, including lists of rulers of many European countries.

• La Gerarchia Cattolica e la Famiglia Pontificia per l'anno 1872; 1882; 1886; and 1888.

• Libro d'Oro della Nobiltà Mediterranea.

• Monumenta Germaniae Historica.

• Notizie per l'anno 1721; 1722; 1723; 1724; 1726; 1728; 1729; 1731; 1732; 1733l 1734; 1735; 1736; 1737; 1740; 1741; 1742; 1744; 1739; 1746; 1749; 1750; 1751; 1752; 1753; 1755; 1756; 1757; 1759; 1760; 1762; 1763; 1764; 1766; 1767; 1770; 1771; 1773; 1775; 1776; 1779; 1781; 1783; 1785; 1786; 1787; 1788; 1789; 1790; 1791; 1795; 1796; 1802; 1806; 1822; 1833; 1834; 1835; 1836; 1837; 1838; 1840; 1842; 1843; 1844; 1845; 1846; 1851; 1852; 1853; 1854; 1856; 1857; and 1858.