1
2
3
by Goleman, Daniel
Published 2002
4
by Yaverbaum, Eric
Published 2004
5
by Bing, Stanley
Published 2004
6
7
by Krames, Jeffrey A.
Published 2004
8
9
10
by Ziglar, Zig
Published 1986
11
by Hughes, William
Published 2004
12
by Chan, Teng Heng
Published 2005
13
by Merrill, Mike
Published 2004
14
by Parkinson, C. Northcote
Published 2003
15
16
by Carnegie, Dale
Published 2009
17
by Benton, D. A.
Published 2009
18
19
by Betof, Edward.
Published 2010
20
by Finzel, Hans
Published 2008