Add WSM'13 paper.

Changelog.txt

@@ -1,3 +1,6 @@
+* 2017-12-01
+	- Added paper ``Self-Censorship on Facebook''
+
 * 2017-11-14
 	- Updated paper ``Analysis of Country-wide Internet Outages Caused by Censorship''
 

header.tpl

@@ -83,7 +83,7 @@
       (<a href="author_reverse.html">reverse</a>) <a href="author.html">author</a> <br />
       Feedback: <a href="mailto:phw@nymity.ch">phw@nymity.ch</a> (<a
       href="https://nymity.ch/openpgp_public_key.txt">OpenPGP</a>) <br />
-      Last updated: <a href="Changelog.txt">2017-11-14</a> <br />
+      Last updated: <a href="Changelog.txt">2017-12-01</a> <br />
       Onion site: <a href="http://3wcwjjnuvjyazeza.onion">3wcwjjnuvjyazeza.onion</a> <br />
       Code: <a href="https://github.com/NullHypothesis/censorbib">GitHub</a>
     </div>

references.bib

@@ -1,3 +1,12 @@
+@inproceedings{Das2013a,
+	author = {Sauvik Das and Adam Kramer},
+	title = {Self-Censorship on {Facebook}},
+	booktitle = {Conference on Weblogs and Social Media},
+	publisher = {AAAI},
+	year = {2013},
+	url = {https://www.aaai.org/ocs/index.php/ICWSM/ICWSM13/paper/viewFile/6093/6350},
+}
+
 @inproceedings{Nasr2017a,
 	author = {Milad Nasr and Hadi Zolfaghari and Amir Houmansadr},
 	title = {The Waterfall of Liberty: Decoy Routing Circumvention that Resists Routing Attacks},