The New Encyclopaedia Britannica : volume 9, micropaedia ready reference
Encyclopaedia Britannica Inc., 2002
 Buku Referensi
The New Encyclopaedia Britannica : volume 6, micropaedia ready reference
Encyclopaedia Britannica Inc., 1998
 Buku Referensi
The New Encyclopaedia Britannica : volume 5, micropaedia ready reference
Encyclopaedia Britannica Inc., 2002
 Buku Referensi
The New Encyclopaedia Britannica : volume 10, micropaedia ready reference
Encyclopaedia Britannica Inc., 2002
 Buku Referensi
The New Encyclopaedia Britannica : volume 12, micropaedia ready reference
Encyclopaedia Britannica Inc., 1998
 Buku Referensi