Flint, Colin, author
Pearson/Prentice Hall, 2007
Buku Teks
Flint, Colin, author
Taylor and Francis Group, 2018
Buku Teks
Flind, Colin, author
Routledge, 2018
Buku Teks
Taylor, Peter J., author
Longman, 1995
Buku Teks
Castles, Francis G.
Allen & Unwin, 1985
Buku Teks