1

2

3
by Button, Robert
Published 2008
RAND National Defense Research Institute

4
by Schank, John F.
Published 2011
RAND

6
by Davis, Lynn E.
Published 2014
RAND

7
by Davis, Paul K.
Published 2008
Rand Corp.

8
by Schank, John F.
Published 2011
Rand Corporation

9
by Martin, Brad
Published 2013
RAND Corporation

10