edited by Andreas C. Papadakis
VCH Publishers,
Buku Referensi
Sage , 2012
Buku Teks
Capon, David Smith, author
John Wiley & Sons, 1999
Buku Teks
The McGraw-Hill Companies, {s.a}
Majalah, Jurnal, Buletin
EMAP, Royal Mail International c/o Smartmail, {s.a}
Majalah, Jurnal, Buletin