Burfeind, James W. , author
Jones and Bartlett Publishers, 2011
Buku Teks
David W. Springer, Albert R. Roberts, editor
Jones and Bartlett Publishers, 2011
Buku Teks
Trojanowicz, Robert C., 1941-, author
Prentice-Hall, 1992
Buku Teks
Weymouth, Anthony
Ljus Forlag, 1944
Buku Teks
McDonald, Roger, author
University of Queensland Press, 1979
Buku Teks