diff --git a/docs/conf.py b/docs/conf.py
index 51d0207..0661db7 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -113,7 +113,7 @@ def build_gallery(app: Sphinx):
         repo_text = ""
         star_text = ""
 
-        if item["repository"]:
+        if "repository" in item:
             repo_text = f'{{bdg-link-secondary}}`repo <{item["repository"]}>`'
 
             try:
diff --git a/docs/gallery.yml b/docs/gallery.yml
index 1d354bd..fcfbb38 100644
--- a/docs/gallery.yml
+++ b/docs/gallery.yml
@@ -230,6 +230,10 @@
   repository: https://github.com/bvanderlei/jupyter-guide-to-linear-algebra
   image: https://bvanderlei.github.io/jupyter-guide-to-linear-algebra/_static/reflection_logo.png
   website: https://bvanderlei.github.io/jupyter-guide-to-linear-algebra/
+# Note: this one has no public repository
+- name: "Python Programming And Numerical Methods: A Guide For Engineers And Scientists"
+  image: https://pythonnumericalmethods.berkeley.edu/_static/book_cover.jpg
+  website: https://pythonnumericalmethods.berkeley.edu/notebooks/Index.html
 - name: "Programming Differential Privacy"
   repository: https://github.com/uvm-plaid/programming-dp
   image: https://uvm-plaid.github.io/programming-dp/_static/logo.png