The Encyclopedia Americana : the international reference work, volume 2
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
The Encyclopedia Americana : the international reference work, volume 7
Americana Corporation, 1960
 Buku Referensi
The Encyclopedia Americana : the international reference work, volume 8
Americana Corporation, 1960
 Buku Referensi