Evers, Hans-Dieter
Brill,, 1972
Buku Teks
Murdock, George Peter, author
The Free Press, 1965
Buku Teks
Brym, Robert J., author
Wadsworth and Cengage Learning, 2013
Buku Teks
New York Grapic Society, 1957
Buku Referensi
Bell, Earl H.
Harper & Row, 1965
Buku Teks