Catholic Encyclopedia - Pope St. Sergius I, d. 701 or 702. www.newadvent.org/cathen/13728b.htm
For All the Saints - With links to other saints with whom Pope St. Sergius I was associated. users.erols.com/saintpat/ss/0908.htm#serg
Popes Through the Ages - Account of the pontificate of St. Sergius, from the book by Joseph Brusher. www.cfpeople.org/Books/Pope/POPEp84.htm
The Ecole Glossary - Began the practice of singing the Agnus Dei during the Mass, and instituted the feast of the exaltation of the Cross. cedar.evansville.edu/~ecoleweb/glossary/sergiusi.html
