Miller, Brian, author
Business Expert Press, 2012
Buku Teks
Clarke, Philip, author
David & Charles, 1973
Buku Teks
Ellis, Albert
Lyll Stuart Inc. , 1988
Buku Teks
Haynes, Colin, author
Aslib, 1995
Buku Teks
McCormack, Mark H., author
Beech Tree Books, 1987
Buku Teks