Unless you're doing a really huge paper, you might want to narrow the topic by country, time period, or whatever. A subject like this can become a lifelong career. A book that might be useful is No author in my library's online card catalog. You can get it on interlibrary loan, if nowhere else. You might find Peggy Seeger's website useful: . I wasn't able to find websites for Frankie Armstrong (British), Faith Petric (885 Clayton Street, San Franisco, California, also the address for the San Fransisco Folk Music Club, and it used to be where they kept their excellent folk library), or Rosalie Sorrels (she lives in or near Boise. Idaho). Also, see what books, etc are available through Folk-Legacy, Front Hall Records, Sing Out Magazine websites. Good luck, gotta run.