Kahn, Alfred J., author
Russel Sage Foundation, 1969
Buku Teks
Johnson, Earl S., author
Macmillan, 1956
Buku Teks
edited by R. Meurig Evans
Macmillan, 1975
Buku Teks
edited by Bruno Stein and S. M. Miller
Aldine Publishing, 1973
Buku Teks
Midgley, James, author
Sage, 2014
Buku Teks