Williams, Robin W.
Alfred A. Knopf, 1963
Buku Teks
Goodyear Publishing, 1972
Buku Teks
edited by Talcott Parsons
Voice of American, 1968
Buku Teks
Merrill, Francis E. (Francis Ellsworth), 1904-1969
Prentice-Hall, 1965
Buku Teks SO
Persell, Caroline Hodges
Harper & Row, 1984
Buku Teks SO