Sherman, Alan, author
Houghton Mifflin, 1992
Buku Teks
Malone, Leo J., author
John Wiley & Sons, 1994
Buku Teks
Robertson, R.A.
Edward Arnold , 1975
Buku Teks
Seese, William S.
Prentice-Hall, 1972
Buku Teks
Malone, Leo J., author
John Wiley & Sons, 1981
Buku Teks