The World book encyclopedia
World Book, 1992
Buku Referensi
The Encyclopedia Americana : the international reference work, volume 2
Americana Corporation, 1960
Buku Referensi
The Encyclopedia Americana : the international reference work, volume 3
Americana Corporation, 1960
Buku Referensi
The Encyclopedia Americana : the international reference work, volume 4
Americana Corporation, 1960
Buku Referensi
The Encyclopedia Americana : the international reference work, volume 5
Americana Corporation, 1960
Buku Referensi