The New Encyclopaedia Britannica : volume 7
Encyclopaedia Britannica Inc., 2003
 Buku Referensi
The New Encyclopaedia Britannica : volume 7
Encyclopaedia Britannica Inc., 1983
 Buku Referensi
The New Encyclopaedia Britannica : volume 7
Encyclopaedia Britannica Inc., 1978
 Buku Referensi
The New Encyclopaedia Britannica : volume 7
Encyclopaedia Britannica Inc., 1983
 Buku Referensi
The New Encyclopaedia Britannica : volume 7, micropaedia ready reference
Encyclopaedia Britannica Inc., 1998
 Buku Referensi