Add data sources for personas

wiki/src/blueprint/personas.mdwn

@@ -27,6 +27,16 @@ This is about [[!tails_ticket 11162]].
 
 # Data sources
 
+- [*Kevin Gallagher & Nasir Memon*, New Me: Understanding Expert and
+  Non-Expert Perceptions and Usage of the Tor Anonymity
+  Network](https://www.usenix.org/system/files/conference/soups2017/soups2017-gallagher.pdf):
+  has some interesting insights on the mental model of Tor for
+  non-expert users.
+
+- [*Ruogu Kang et al.*, “My Data Just Goes Everywhere:” User Mental
+  Models of the Internet and  Implications for Privacy and
+  Security](https://www.usenix.org/system/files/conference/soups2015/soups15-paper-kang.pdf).
+
 - [*Rick Wash & Emilee Rader*, Too Much Knowledge? Security Beliefs and
   Protective Behaviors Among United States Internet
   Users](http://www.rickwash.com/papers/security-survey.pdf): studies a