Oxford University Press, 1990
Buku Referensi
Westen, Drew, author
John Wiley & Sons Australia, 2006
Buku Teks
American Book Company, [1914]
Buku Referensi
Victoria Neufeldt, Andrew N. Sparks, editor
Simon & Schuster, 1989
Buku Referensi
Neufeldt, Victoria, author
Prentice Hall ; Modern English Press, 1993
Buku Referensi