Prentice-Hall, 1970
Buku Teks
Hertz, Heinrich Rudolf
Garland Pub., 1994
Buku Teks
Kennedy, Richard
Macmillan Publishing Co. Inc, 1982
Buku Teks
Freedman, Lawrence, author
Oxford University Press, 2000
Buku Teks
Kennedy, Raymond
Yale University Press, 1945
Buku Referensi