The Encyclopedia Americana : volume 7
Grolier, 1994
 Buku Referensi
The Encyclopedia Americana : volume 7
Americana Corporation, 1977
 Buku Referensi
The Encyclopedia Americana : volume 7
Americana Corporation, 1964
 Buku Referensi
Collier's encyclopedia; Volume 7
Macmillan, 1990
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The World book encyclopedia : volume 7
World Book, 1985
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