Bowie, Fiona, author
BlackWell Publishing, 2005
Buku Teks
Hammond, Peter, author
Macmillan, 1978
Buku Teks
Rosman, Abraham, author
Random House, 1989
Buku Teks
Kottak, Conrad Phillip, author
McGraw-Hill, 2012
Buku Teks
Beals, Ralph L
Macmillan, 1954
Buku Teks