Catholic Online: St. Catherine of Siena - Brief hagiography of this Doctor of the Church, and patron saint of Italy. - http://www.catholic.org/saints/saint.php?saint_id=9
Catherine of Siena, Saint - Biographical article in the Columbia Encyclopedia, 6th ed. Includes bibliography. - http://www.bartleby.com/65/ca/CathrinSi.html
Women Saints, Doctors of the Church - Short feature story by Jone Johnson Lewis on SS. Teresa of Avila and Catherine of Siena, the first two women Doctors of the Church. - http://womenshistory.about.com/library/weekly/aa021599.htm?once=true&
St. Catherine of Sienna, Virgin - From Fr. Alban Butler's Lives of the Saints. - http://www.ewtn.com/library/MARY/CSIENA.htm
St. Catherine of Sienna, 1347-1380 - Essay on her life, from the book "The Saints: A Concise Biographical Dictionary," edited by John Coulson. - http://www.cin.org/saints/cathsiena.html
Catholic Encyclopedia: St. Catherine of Siena - Third Order Dominican, hermit, reformer, mystic, d. 1380. Biographical article by Edmund G. Gardner. - http://www.newadvent.org/cathen/03447a.htm
Domestic Church: Saint Catherine of Siena - Three accounts: for children ages 0-8, children 8-14, and ages 14-adult. - http://www.domestic-church.com/CONTENT.DCC/19980301/SAINTS/ST_CATH.HTM