Doorley, Scott, author
John Wiley & Sons, 2012
Buku Teks
Tanzer, Milt, author
Prentice-Hall, 1996
Buku Referensi
Elliot, Rose, author
Chapmans Publisher Ltd., 1994
Buku Referensi
Minrath, William R., author
D. Van Nostrand, 1956
Buku Teks
Lagin, Lazer
Foreign Languages Publishing House, [date of publication not identified]
Buku Teks