Encyclopaedia Britannica : volume 9
Encyclopaedia Britannica Inc., 1968
 Buku Referensi
Encyclopaedia universalis : volume 9
Encyclopaedia Universalis France S.A. , 1989
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The New Encyclopaedia Britannica : volume 9
Encyclopaedia Britannica Inc., 1988
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The New Encyclopaedia Britannica : volume 9
Encyclopaedia Britannica Inc., 2003
 Buku Referensi
The New Encyclopaedia Britannica : volume 9
Encyclopaedia Britannica Inc., 1978
 Buku Referensi