Alpert, Jack N., author
Springer, 2012
eBooks
Pagliarulo, Michael A
Elsevier Mosby, 2012
Buku Teks
United Nations Departemen of Public Information, 1995
Buku Teks
Gach, Michael Reed
Piatkus, 1990
Buku Teks
Chipchase, Lucy, author
Butterworth-Heinemann, 2001
Buku Teks