Gordon, Morton J.
Prentice-Hall, 1961
Buku Teks
Oosterhoff, Jenneke A., author
Routledge, 2009
Buku Teks
edited by Sohn Ho-min
University of Hawaii, 2006
Buku Teks
Shetter, William Z., author
Martinus Nijhoff, 1988
Buku Teks
Karlsson, Fred
Routledge, 1999
Buku Teks