Kelly, David, author
Hollis & Caster , 1952
Buku Teks
Fellner, William, 1905-, author
Alfred A. Knopf, 1949
Buku Teks
Martin, Samuel E., author
Tuttle Publishing, 2008
Buku Teks
Karachi, Umma Publishing
Buku Teks
Departemen Pendidikan dan Kebudayaan, 1986
Buku Teks