diff --git a/content/zettels/feedforward_control.md b/content/zettels/feedforward_control.md
index f057c4d..cb4ae58 100644
--- a/content/zettels/feedforward_control.md
+++ b/content/zettels/feedforward_control.md
@@ -225,6 +225,9 @@ This can be solved by using **snap feedforward**
 
 {{< figure src="/ox-hugo/feedforward_schematic_snap.png" >}}
 
+
+## Bibliography {#bibliography}
+
 <style>.csl-entry{text-indent: -1.5em; margin-left: 1.5em;}</style><div class="csl-bib-body">
   <div class="csl-entry"><a id="citeproc_bib_item_1"></a>Boerlage, M., M. Steinbuch, P. Lambrechts, and M. van de Wal. 2003. “Model-Based Feedforward for Motion Systems.” In <i>Proceedings of 2003 IEEE Conference on Control Applications, 2003. CCA 2003.</i> doi:<a href="https://doi.org/10.1109/cca.2003.1223174">10.1109/cca.2003.1223174</a>.</div>
   <div class="csl-entry"><a id="citeproc_bib_item_2"></a>Lambrechts, P., M. Boerlage, and M. Steinbuch. 2004. “Trajectory Planning and Feedforward Design for High Performance Motion Systems.” In <i>Proceedings of the 2004 American Control Conference</i>. doi:<a href="https://doi.org/10.23919/acc.2004.1384042">10.23919/acc.2004.1384042</a>.</div>