Beals, Ralph L., author
Macmillan, 1959
Buku Teks
Oliver, Chad
Harper & Row , 1981
Buku Teks
Alland, Alexander
John Wiley & Sons,Inc., 1980
Buku Teks
Holmes, Lowell D.
The Ronald Press, 1965
Buku Teks
Titiev, Mischa
Holf, Rinehart and Winston, 1961
Buku Teks