Williams, Malcolm, 1953-, author
Routledge, 2000
Buku Teks
Lembaga Penelitian Unpad,
Majalah, Jurnal, Buletin
Blalock, Hubert M., author
Sage Publications, 1982
Buku Teks
Rosenberg, Alexander, author
John Hopkins University Press, 1980
Buku Teks
Natanson, Maurice, author
Random House, 1963
Buku Teks