William Mathias
- Digest of reviews from Classics Today with cover art and purchase information.
- http://www.classicstoday.com/digest/pdigest.asp?perfidx=11611

Mathias,William
- Listing of his clarinet works noting instruments used and related works by others.
- http://www.woodwind.org/Databases/Composers/Names/006551.html

William Mathias (1934-1992)
- Listing at The Lied and Art Song Texts Page with lyrics to selected vocal works.
- http://www.recmusic.org/lieder/m/mathias.html

OUP: Mathias
- Article from Oxford University Press with photograph, catalogue of works, discography, and MP3 audio sample.
- http://www.oup.co.uk/music/repprom/mathias/

Mathias, William
- Entry from the Gilder-MusicWeb Dictionary of Composers with brief biography and chronological list of works.
- http://www.musicweb.uk.net/Classpedia/Mathias.htm

Mathias, William James
- Brief biography noting stylistic tendencies, studies, and output of works from the Grove Concise Dictionary of Music entry at WQXR radio.
- http://www.wqxr.com/cgi-bin/iowa/cla/learning/grove.html?record=5844