Bremness, Lesley, author
Dorling Kindersley, 1988
Buku Teks
Hey, Barbara, author
New Holland, 1994
Buku Teks
Strong, William S., author
MIT Press, 1981
Buku Teks
John, Arthur W., author
Thames and Hudson, 1988
Buku Teks
Richard Mabey, editor
Penguin , 1991
Buku Referensi