The New book of knowledge : volume 2
Grolier Incorporated, 1997
 Buku Referensi
The New Encyclopaedia Britannica : volume 2
Encyclopaedia Britannica Inc., 1988
 Buku Referensi
An Encyclopaedia of New Zealand : volume 2
editor, A.H. McLintock
R. E. Owen, Government printer, 1966
 Buku Referensi
The New Encyclopaedia Britannica : volume 2
Encyclopaedia Britannica Inc., 2003
 Buku Referensi
The New Encyclopedia Britannica : volume 2
Encyclopedia Britannica, 1983
 Buku Referensi