Mayes, Pat
Longman, 1986
Buku Teks
Bornstein, Robert F
Washington D.C, 2002
Buku Teks
Brettell, Caroline
Polity Press, 2016
Buku Teks
Louise Durning, Richard Wrigley, editor
John Wiley & Sons, 2000
Buku Teks
Archer, John
Cambridge University Press, 2002
Buku Teks