The New Encyclopaedia Britannica : volume 6, micropaedia ready reference
Encyclopaedia Britannica Inc., 1998
 Buku Referensi
The New Encyclopaedia Britannica : volume 12, micropaedia ready reference
Encyclopaedia Britannica Inc., 1998
 Buku Referensi
The New Encyclopaedia Britannica : volume 11, micropaedia ready reference
Encyclopaedia Britannica Inc., 1998
 Buku Referensi
The New Encyclopaedia Britannica : volume 4, micropaedia ready reference
Encyclopaedia Britannica Inc., 1988
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The New Encyclopaedia Britannica : volume 3, micropaedia ready reference
Encyclopaedia Britannica Inc., 1998
 Buku Referensi