1
by De Bono, Edward, 1933-
Published 1996
2
by Blackburn
Published 1999
3
by de Bono, 1933-
Published 1995
4
by De Bono, 1933-
Published 1996
5
by Buzan
Published 2004
6
by Buzan
Published 2003
7
by Buzan
Published 2001
8
by Buzan
Published 2002
9
by De Bono
Published 2000