edited by Edward Conrad Smith and Arnold John Zurcher
Barnes & Noble, 1966
Buku Teks
McCarthy, Eugene J.
Macmillan, 1962
Buku Teks
Makkai, Adam
Barrons, 1995
Buku Teks
Cummings, Paul, author
St. Martin's Press, 1966
Buku Referensi
Evans, Bergen, 1904-, author
Random House, 1957
Buku Referensi