Corner, E.J.H.
The World Publishing Company, 1964
Buku Teks
Raven, Peter H., author
Worth Publisher, 1986
Buku Referensi
Laetsch, Watson M., author
Little, Brown, 1979
Buku Teks
Attenborough, David
BBC Worldwide Limited, 2005
Multimedia
Attenborough, David
BBC Worldwide Limited, 2005
Multimedia