edited by N.R. Saunders and K.M. Dziegielewska
Harwood Academic, 2000
Buku Teks
Schniederjan, Matthew J., author
Wolters Kluwer, 2011
Buku Teks
Barr, Murray L., author
Harper and Row, 1983
Buku Teks
Mogadam, Michael, author
New American Library, 2001
Buku Teks
edited by Lloyd A. Horrocks, G. Brian Ansell, Giuseppe Porcellati
Raven Press, 1985
Buku Teks