diff --git a/.eleventy.js b/.eleventy.js
index 984d7a9..a447475 100644
--- a/.eleventy.js
+++ b/.eleventy.js
@@ -62,6 +62,18 @@ module.exports = function (eleventyConfig) {
             .length;
     });
 
+    eleventyConfig.addCollection("series", function (collectionApi) {
+        return collectionApi.getAll()
+            .filter(p => p.data?.series)
+            .sort((p0, p1) => p0.data.order - p1.data.order)
+            .reduce((series, post) => {
+                series[post.data.series] = series[post.data.series] ?? [];
+                series[post.data.series].push(post);
+                console.log(series);
+                return series;
+            }, {});
+    });
+
     return {
         // Pre-process *.md files with: (default: `liquid`)
         markdownTemplateEngine: "njk",
diff --git a/src/_includes/layouts/article.njk b/src/_includes/layouts/article.njk
index ef52841..f96629e 100644
--- a/src/_includes/layouts/article.njk
+++ b/src/_includes/layouts/article.njk
@@ -18,15 +18,13 @@ layout: base.njk
         <div class="tab-card">
             <div class="title">{{ strings.article.seriesParts }}</div>
             <div class="card">
-                {%- for post in collections.all %}
-                {% if post.data.series == series %}
+                {%- for post in collections.series[series] %}
                 <div class="p-2">
                     <a href="{{ post.url | url }}"
                        class="list-group-item list-group-item-action{% if post.url == page.url %} fw-bold{% endif %}">
                         {{ post.data.title }}
                     </a>
                 </div>
-                {% endif %}
                 {%- endfor %}
             </div>
         </div>
diff --git a/src/de/services/matrix/setup/part-1.md b/src/de/services/matrix/setup/part-1.md
index 60bcc91..51a83d9 100644
--- a/src/de/services/matrix/setup/part-1.md
+++ b/src/de/services/matrix/setup/part-1.md
@@ -4,6 +4,7 @@ service: matrix
 title: Werde Teil der Matrix - Matrix Teil 1
 summary: Erfahre Schritt für Schritt, wie du deinen eigenen Matrix Account einrichten kannst.
 series: matrix-setup
+order: 1
 tags:
   - Tutorial
   - Matrix
diff --git a/src/de/services/matrix/setup/part-2.md b/src/de/services/matrix/setup/part-2.md
index 2ff36a9..9b563f6 100644
--- a/src/de/services/matrix/setup/part-2.md
+++ b/src/de/services/matrix/setup/part-2.md
@@ -4,6 +4,7 @@ service: matrix
 title: Sichere Chats mit Matrix – Matrix Teil 2
 summary: Erfahre, was es mit Ende-zu-Ende-Verschlüsselung und der Verifizierung von Kontakten auf sich hat.
 series: matrix-setup
+order: 2
 tags:
   - Tutorial
   - Matrix