References:

1. "U.S. voters warned by bishop," Los Angeles Times, reprinted in the Toronto Star, 2004-MAY-15, Page A16.
2. Michael Sheridan, "A pastoral letter to the Catholic faithful of the Diocese of Colorado Springs on the duties of Catholic politicians and voters," at: http://www.diocesecs.org
3. Robert Broderick, Ed., "Catholic Encyclopedia: Revised and updated edition," Nelson, (1987), Page 272.  Read reviews or order this book safely from Amazon.com online book store
4. "Catechism of the Catholic Church," Topic 1782.
5. Ibid., 1783.
6. Ibid., 2032 and Code of Canon Law 747.2.
7. Joseph Cardinal Ratzinger, "Doctrinal note on some questions regarding the participation of Catholics in political life," Offices of the Congregation for the Doctrine of the Faith, 2002-NOV-24, at: http://www.vatican.va/
8. "Ralph Nader on Abortion," at: http://www.issues2000.org
9. Pope Paul VI, "Humanae Vitae. Encyclical of Pope Paul VI on the regulation of birth," 1968-JUL-25, at: http://www.vatican.va/
10. "KENNEDY TO KERRY: Kerry, Catholics and the White House," ReligionLink.org, 2004-MAY-03, at: http://www.religionlink.org/
11. John-Henry Westen, "US Bishops Set to Tell Catholics Opposed to Teaching on Abortion or Homosexuality not to Receive Communion", LifeSiteNews, 2006-OCT-20, at: http://www.lifesite.net/