diff --git a/header.tpl b/header.tpl
index b90780d..2f21be4 100644
--- a/header.tpl
+++ b/header.tpl
@@ -189,7 +189,7 @@
           <div class="menu-item">
             <img class="top-icon" src="img/update-icon.svg" alt="update icon"/>
             <a
-            href="https://github.com/NullHypothesis/censorbib/commits/master">Last update: 2023-04-24</a>
+            href="https://github.com/NullHypothesis/censorbib/commits/master">Last update: 2023-05-03</a>
           </div>
           <div class="menu-item">
             <img class="top-icon" src="img/donate-icon.svg" alt="donate icon"/>
diff --git a/references.bib b/references.bib
index 1b0fba4..c47d98c 100644
--- a/references.bib
+++ b/references.bib
@@ -1,3 +1,50 @@
+@article{razaghpanah2016a,
+	title        = {Exploring the Design Space of Longitudinal Censorship Measurement Platforms},
+	author       = {Abbas Razaghpanah and Anke Li and Arturo Filast{\`{o}} and Rishab Nithyanand and Vasilis Ververis and Will Scott and Phillipa Gill},
+	year         = {2016},
+	volume       = {abs/1606.01979},
+	eprinttype   = {arXiv},
+	eprint       = {1606.01979},
+	url          = {http://arxiv.org/abs/1606.01979},
+}
+
+@article{Ververis2017b,
+	title        = {Network interference in Latin America: Evaluating network measurements to detect information controls and Internet censorship},
+	author       = {Vasilis Ververis and Olga Khrustaleva and Eliana Quiroz},
+	year         = {2017},
+	month        = {11},
+	issn         = {2175-9596},
+	url          = {https://lavits.org/wp-content/uploads/2018/04/32-Vasilis-Ververis-Olga-Khrustaleva-e-Eliana-Quiroz.pdf},
+}
+
+@article{Ververis2020a,
+	title        = {Cross-Country Comparison of Internet Censorship: A Literature Review},
+	author       = {Ververis Vasilis and Marguel Sophia and Fabian Benjamin},
+	year         = {2020},
+	journal      = {Policy \& Internet},
+	publisher    = {Wiley Online Library},
+	volume       = {12},
+	number       = {4},
+	pages        = {450--473},
+    url          = {https://onlinelibrary.wiley.com/doi/full/10.1002/poi3.228},
+}
+
+@inproceedings{Ververis2021a,
+	title        = {Understanding Internet Censorship in Europe: The Case of Spain},
+	author       = {Vasilis Ververis and Tatiana Ermakova and Marios Isaakidis and Simone Basso and Benjamin Fabian and Stefania Milan},
+	year         = {2021},
+	booktitle    = {13th ACM Web Science Conference 2021},
+	location     = {Virtual Event, United Kingdom},
+	publisher    = {Association for Computing Machinery},
+	address      = {New York, NY, USA},
+	series       = {WebSci '21},
+	pages        = {319–328},
+	doi          = {10.1145/3447535.3462638},
+	isbn         = {9781450383301},
+	url          = {https://doi.org/10.1145/3447535.3462638},
+	numpages     = {10},
+}
+
 @inproceedings{Wu2023a,
 	author = {Mingshi Wu and Jackson Sippe and Danesh Sivakumar and Jack Burg and Peter Anderson and Xiaokang Wang and Kevin Bock and Amir Houmansadr and Dave Levin and Eric Wustrow},
 	title = {How the {Great Firewall} of {China} Detects and Blocks Fully Encrypted Traffic},