Watt, Homer A.
Barnes & Noble, 1957
Buku Referensi
edited by Joseph T. Shipley
Littlefield, Adams, 1960
Buku Referensi
Oxford University Press, 1996
Buku Referensi
Katzner, Kenneth
John Wiley & Sons, 1994
Buku Referensi
Hisamatsu, Senichi
Kodansha International, 1978
Buku Referensi