Cyril, Monk, and Methodius B
- Illustrated biography of SS. Cyril and Methodius.
- http://www.saintpatrickdc.org/ss/0214.htm#cyri

Catholic Online: Sts. Cyril and Methodius
- Reflection on their lives.
- http://www.catholic.org/saints/saint.php?saint_id=39

Grande Munus
- Encyclical of Pope Leo XIII, on SS. Cyril and Methodius, promulgated in 1880.
- http://www.papalencyclicals.net/Leo13/l13cym.htm

St. Cyril and St. Methodius
- The story of these two brothers, suitable for children. Preformatted line breaks can make this difficult to read.
- http://www.tntt.org/vni/tlieu/saints/St0214.htm

Cyril and Methodius, Saints
- Short note on the fathers of Slavonic literature, in the Columbia Encyclopedia.
- http://www.bartleby.com/65/cy/CyrilNMe.html

Cyril and Methodius, Missionaries to the Slavs
- Outline of their missionary activities. With prayer in traditional and contemporary language.
- http://elvis.rowan.edu/~kilroy/JEK/02/14.html

Slavorum Apostoli
- Commemoration of the Eleventh Centenary of the Evangelizing Work of SS. Cyril and Methodius. Encyclical of Pope John Paul II, promulgated in 1985.
- http://www.ewtn.com/library/ENCYC/JP2SLAV.HTM

Lives of the Saints: SS Cyril and Methodius
- From Alban Butler's Lives of the Saints.
- http://www.cin.org/saints/c&m.html

Catholic Encyclopedia: Sts. Cyril and Methodius
- Also called Constantine and Methodius. Biography of these ninth-century brothers, Apostles of the Slavs.
- http://www.newadvent.org/cathen/04592a.htm