1
by Summers
Published 2009
2
by Zeithaml
Published 2004
3
by Vasconcellos
Published 2004
4
by Clute
Published 2009
5
Published 2012
6
by Carpenter
Published 2000
7
by Gould
Published 1992
8
by Hough
Published 2010
9
by Gould
Published 2001
10
Published 2000
11
by Hubbard
Published 2003
12
by Wallace
Published 2011
13
by Srinivasan
Published 2012
14
by Dlugacz
Published 2006
15
by Harburn
Published 1991
16
17
by OMAN
Published 1997
18
Published 1996
19
by HILES
Published 1993
20
by Oakland
Published 1993