Boyle, Michael P., author
Routledge , 2015
Buku Teks
Schwandt, Thomas A., author
Sage, 1988
Buku Teks
edited by E.G. Stanford, J.H. Fearon, W.J. McGonnagle
CRC Press, 1968
Buku Teks
Marcel Das, Peter Ester, Lars Kaczmirek, editor
Routledge, 2011
Buku Teks
Shuchman, Abe
Holt, Rinehart and Winston, Inc., 1963
Buku Teks