diff --git a/kfet/static/kfet/js/kfet.api.js b/kfet/static/kfet/js/kfet.api.js
index a655786d..1339f284 100644
--- a/kfet/static/kfet/js/kfet.api.js
+++ b/kfet/static/kfet/js/kfet.api.js
@@ -165,24 +165,11 @@ class ModelObject {
 
     /**
      * Returns a string value for the model, to use in comparisons
-     * @see {@link Models.ModelObject.compare|ModelObject.compare}
+     * @see {@link Models.TreeNode.compare|TreeNode.compare}
      */
     comparevalue() {
         return this.id.toString();
     }
-
-    /**
-     * Compare function between two instances of the model
-     * by serializing them using comparevalue().
-     * @abstract
-     * @param {a} Models.ModelObject
-     * @param {b} Models.ModelObject
-     * @see {@link Models.ModelObject.comparevalue|ModelObject.comparevalue}
-     */
-    static compare(a, b) {
-        return a.comparevalue().localeCompare(b.comparevalue());
-    }
-
 }
 
 
@@ -552,7 +539,7 @@ class Article extends ModelObject {
      * @see {@link Models.ModelObject.compare|ModelObject.compare}
      */
     comparevalue() {
-        return a.name;
+        return this.name;
     }
 
     // Take care of 'price' type
@@ -574,6 +561,13 @@ class TreeNode {
         this.parent = null;
         this.children = []; 
     }
+
+    static compare(a, b) {
+        var a_serial = a.content.comparevalue();
+        var b_serial = b.content.comparevalue();
+
+        return a_serial.localeCompare(b_serial)
+    }
 }