The New Encyclopaedia Britannica : volume 12
Encyclopaedia Britannica Inc., 1988
 Buku Referensi
The New Encyclopaedia Britannica : volume 12, micropaedia ready reference
Encyclopaedia Britannica Inc., 2002
 Buku Referensi
The New Encyclopaedia Britannica : volume 12, micropaedia ready reference
Encyclopaedia Britannica Inc., 1998
 Buku Referensi
Encyclopaedia Britannica : volume 12
Encyclopaedia Britannica Inc., 1967
 Buku Referensi
Encyclopaedia Britannica : volume 12
Encyclopaedia Britannica Inc., 1968
 Buku Referensi