diff --git a/fetch_pdfs.py b/fetch_pdfs.py
index aef4c20..49967ae 100755
--- a/fetch_pdfs.py
+++ b/fetch_pdfs.py
@@ -79,14 +79,10 @@ def main(file_name, output_dir):
             ext = ext[1:]
 
         if ext not in ["pdf", "ps"]:
-            print("Skipping %s because it's not a pdf or ps file." % url,
-                  file=sys.stderr)
             continue
 
         file_name = os.path.join(output_dir, ext, bibkey + ".%s" % ext)
         if os.path.exists(file_name):
-            print("Skipping %s because we already have it." % file_name,
-                  file=sys.stderr)
             continue
 
         download_pdf(url, file_name)
diff --git a/header.tpl b/header.tpl
index fd73ca0..f4745cd 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: 2023-07-11</a>
+            href="https://github.com/NullHypothesis/censorbib/commits/master">Last update: 2023-07-16</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 7982617..f9d44dd 100644
--- a/references.bib
+++ b/references.bib
@@ -68,6 +68,14 @@
 	publisher = {},
 	year = {2023},
 	url = {https://www.petsymposium.org/foci/2023/foci-2023-0016.pdf},
+
+@inproceedings{Waheed2022a,
+	author = {Asim Waheed and Sara Qunaibi and Diogo Barradas and Zachary Weinberg},
+	title = {Darwin's Theory of Censorship: Analysing the Evolution of Censored Topics with Dynamic Topic Models},
+	year = {2022},
+	publisher = {ACM},
+	url = {https://research.owlfolio.org/pubs/2022-darwin-censorship.pdf},
+	booktitle = {Workshop on Privacy in the Electronic Society},
 }
 
 @inproceedings{Ververis2021a,