Keylor, William R., 1944-, author
Oxford University Press, 1996
Buku Teks
Dance, E.H., author
Longman, 1937
Buku Teks
Carlson, Paul A., author
South Western, 1957
Buku Teks
edited by E.M. Kirkpatrick ; assistant editors, C.M. Schwarz ... [and others]
Chambers, 1983
Buku Referensi
Berle, Adolf A., Jr., author
Harcourt, Brace, 1954
Buku Klasik