remove empty bibliography

content/zettels/right_half_plane_zeros.md

@@ -22,9 +22,3 @@ Right Half Plane (RHP) Zeros are present in a broad range of systems.
     -   The frequency of the RHP zero should be outside the controller bandwidth.
         It therefore impose a fundamental limitation to the controller bandwidth.
         The reason is that inside the control bandwidth, the controller basically inverts the plant, and the inverse of a RHP zero is an unstable pole.
-
-
-## Bibliography {#bibliography}
-
-<style>.csl-entry{text-indent: -1.5em; margin-left: 1.5em;}</style><div class="csl-bib-body">
-</div>