Sage Publications, 1987
Buku Teks
Soule, Barbara M., author
Mosby , 1995
Buku Teks
Balalaev, G. A.
MIR Publishers, 1972
Buku Teks
Litton, Roger A., 1944-, author
Avebury, 1990
Buku Teks
edited by David M. B. Hall
Oxford University Press, 1991
Buku Teks