Duffus, C.M., author
John Wiley & Sons, 1980
Buku Teks
Paul F. Lazarsfeld ... [and others]
Basic Books, 1967
Buku Teks
Solomon, Irving I., author
New American Library , 1968
Buku Teks
edited by Lynne Hayman
CT Meckler, 1990
Buku Teks
Brown, T. Merritt, author
Macmillan, 1970
Buku Teks