Simon, Julian L.
Random House , 1978
Buku Teks
edited, Bridget Somekh, Cathy Lewin
Sage Publications , 2005
Buku Teks
Leavitt, Fred, author
C. Brown Publishers , 1991
Buku Teks
Simon, Julian L.
Random House, 1978
Buku Teks
Bryman, Alan, author
Oxford University Press, 2016
Buku Teks