Whitmore, T.C., author
Oxford University Press, 1986
Buku Teks
Whitmore, T.C., author
Clarendon Press, 1990
Buku Teks
Francis, W.D., author
Australian Government Publishing Service, 1981
Buku Teks
Margaret Kalacska, G. Arturo Sanchez-Azofeifa, editor
CRC Press, Taylor & Francis Group, 2008
Buku Teks
Veevers-Carter, W., author
Oxford University Press , 1984
Buku Teks