Stambler, Irwin, and Grelun Landon. Encyclopedia of Folk, Country and Western Music. New York: St. Martin's Press, 1969.
Original Carter Family Collection. Southern Folklife Collection,
University of North Carolina at Chapel Hill.
http://ils.unc.edu/dolma/carter.html
Background information about the Carter family, photographs from the
collection, and a short audio clip of "Keep on the Sunny Side" are
included.