remove empty bibliography

content/zettels/test.md

@@ -465,7 +465,7 @@ Numbering can be continued by using `+n` option as shown below.
 ```
 <div class="src-block-caption">
   <span class="src-block-number"><a href="#code-snippet--lst:tikz-test-general-control-names">Code Snippet 4</a>:</span>
-  Tikz code that is used to generate <a href="#org587cbdd">5</a>
+  Tikz code that is used to generate <a href="#orgd87d21e">5</a>
 </div>
 
 <a id="figure--fig:test-general-control-names"></a>