Baker's Biographical Dictionary of Musicians. ed. Nicolas Slonimsky. New York: Schirmer Books, 2001.

Encyclopedia of Rock Stars. ed. Luke Crampton and Dafydd Rees. Limited, London: Dorling Kindersley, 1996.

"Joplin, Janis." Harvard Biographical Dictionary of Music, ed. Don Michael Randal.
Cambridge, MA: Belknap Press of Harvard University Press, 1996, p. 428-429.

The New Grove Dictionary of American Music. ed. H. Wiley Hitchock and Stanley Sadie. New York: Macmillan Press Ltd., 1986.

The Oxford Companion to Popular Music. ed. Peter Gammond. New York: Oxford University PRess, 1991. 

The Rock Who's Who, Second Edition. ed. Brock Helander. New York: Schirmer Books, 1996.

The Rolling Stone Encyclopedia of Rock and Roll, 3rd Edition. ed. Holly George-Warren and Patricia Romanowski. New York: Rollingstone Press, 2001.

"Slick, Grace." Harvard Biographical Dictionary of Music, ed. Don Michael Randal. Cambridge, MA: Belknap Press of Harvard University Press, 1996, p. 844.