4 links
IMDb: Stephen Sondheim
us.imdb.com
Filmography and television shows based on his compositions or using his music, plus acting and miscellaneous credits.
Sondheim Notes
larryavisbrown.homestead.com
Articles on Sondheim's musicals in the 1970s, such as "Little Night Music," "Pacific Overtures," and "Sweeney Todd."
Stephen Sondheim Reference Guide
geocities.com
Features listing of shows, songs, recordings, and chronology.