Encyclopædia Britannica: Methodius - An account of his missionary endeavors, and a short bibliography. In the 11th edition (1911). - http://encyclopedia.jrank.org/MEC_MIC/METHODIUS_c_825_885_.html
The Ecole Glossary: Methodius - Short biography, by Karen Rae Keck. - http://www2.evansville.edu/ecoleweb/glossary/methodios.html
Patron Saints Index: Methodius - Illustrated profile of the Apostle of the Slavs. - http://www.catholic-forum.com/saints/saintm10.htm