Lexicon Publications , 2004
Buku Referensi
edited by Thomas Davidson
W. & R. Chambers, 1901
Buku Referensi
Andrews, Edmund, author
Chicago Academy of Sciences, 1944
Buku Referensi
Crew, Frederick, author
Random House, 1987
Buku Teks
Crews, Frederick, author
Random House, 1984
Buku Teks