Hillenbrand, Laura, author
Ballantine Books, 2001
Buku Teks
O`Hara, John, author
New South Wales University Press, 1988
Buku Teks
Charles Scribner's Sons, 1964
Buku Referensi
Myrdal, Gunnar, 1898-, author
Harper & Brothers , 1944
Buku Teks
Kongressional Quarterly, 2000
Buku Teks