Drummond, Michael F.
Oxford Univesity Press, 1980
Buku Teks
Drummond, Michael F.
Oxford University Press, 1989
Buku Teks
Adler, Hans A.
Indiana University Press, 1971
Buku Teks
McConnell, Charles R.
Jones and Bartlett, 2011
Buku Teks
edited by Leslie Neal-Boylan
Wiley-Blackwell, 2011
Buku Teks