1
Published 1996
2
Published 1990
3
Published 2003
4
Published 2005
5
Published 2006
6
Published 2007
7
Published 2008
8
Published 2007
9
Published 2008
10
Published 2007
11
Published 2009
12
Published 2010
13
Published 2014
14
Published 2009
15
Published 2010
16
Published 2012
17
by Cunningham,
Published 1996
18
Published 1998
19
by Mannheim,
Published 1998
20
Published 2003