edited by Louis Moss and Harvey Goldstein
University of London Institute of Education, 1979
Buku Teks SO
Frey, James H.
Sage Publications, 1983
Buku Referensi
Fern, Edward F.
Sage, 2001
Buku Teks SO
Magnusson, Eva
Cambridge University Press, 2015
Buku Teks SO
Brinkmann, Svend
Sage, 2015
Buku Teks