Bechhofer, Frank
Routledge, 2000
Buku Teks SO
Marshall, Catherine
Sage, 1999
Buku Teks SO
Lee, Raymond M.
Open University Press, 2000
Buku Teks SO
edited by Sugata Dasgupta
Impex India, 1967
Buku Teks SO
Babbie, Earl R.
Wadsworth and Cengage Learning, 2013 (International edition)
Buku Teks SO