Katz, William A., 1924-, author
Holt, Rinehart and Winston, 1979
Buku Teks
edited Charles Singer, E.J. Holymyard, A.R. Hall
At The Clarendon Press, 1957
Buku Teks
Ronan, Jana Smith, author
Libraries Unlimited, 2003
Buku Teks
Evans, G.O., author
Taylor and Francis, 2009
Buku Teks
Santayana, George, author
Scribner, 1953
Buku Teks