diff --git a/content/zettels/charge_amplifiers.md b/content/zettels/charge_amplifiers.md
index b1301b5..9e96416 100644
--- a/content/zettels/charge_amplifiers.md
+++ b/content/zettels/charge_amplifiers.md
@@ -4,10 +4,6 @@ author = ["Thomas Dehaeze"]
 draft = false
 +++
 
-Backlinks:
-
--   [Signal Conditioner]({{< relref "signal_conditioner" >}})
-
 Tags
 : [Electronics]({{< relref "electronics" >}})
 
@@ -21,19 +17,19 @@ This can be typically used to interface with piezoelectric sensors.
 
 ## Basic Circuit {#basic-circuit}
 
-Two basic circuits of charge amplifiers are shown in Figure [1](#org9ffcf40) (taken from ([Fleming 2010](#orgaceef58))) and Figure [2](#org37bd87f) (taken from ([Schmidt, Schitter, and Rankers 2014](#org683b96e)))
+Two basic circuits of charge amplifiers are shown in Figure [1](#org3aa62a6) (taken from ([Fleming 2010](#orgd8b7cb4))) and Figure [2](#org18afeb8) (taken from ([Schmidt, Schitter, and Rankers 2014](#orga9d9a6b)))
 
-<a id="org9ffcf40"></a>
+<a id="org3aa62a6"></a>
 
 {{< figure src="/ox-hugo/charge_amplifier_circuit.png" caption="Figure 1: Electrical model of a piezoelectric force sensor is shown in gray. The op-amp charge amplifier is shown on the right. The output voltage \\(V\_s\\) equal to \\(-q/C\_s\\)" >}}
 
-<a id="org37bd87f"></a>
+<a id="org18afeb8"></a>
 
 {{< figure src="/ox-hugo/charge_amplifier_circuit_bis.png" caption="Figure 2: A piezoelectric accelerometer with a charge amplifier as signal conditioning element" >}}
 
 The input impedance of the charge amplifier is very small (unlike when using a voltage amplifier).
 
-The gain of the charge amplified (Figure [1](#org9ffcf40)) is equal to:
+The gain of the charge amplified (Figure [1](#org3aa62a6)) is equal to:
 \\[ \frac{V\_s}{q} = \frac{-1}{C\_s} \\]
 
 
@@ -53,6 +49,6 @@ The gain of the charge amplified (Figure [1](#org9ffcf40)) is equal to:
 
 ## Bibliography {#bibliography}
 
-<a id="orgaceef58"></a>Fleming, A.J. 2010. “Nanopositioning System with Force Feedback for High-Performance Tracking and Vibration Control.” _IEEE/ASME Transactions on Mechatronics_ 15 (3):433–47. <https://doi.org/10.1109/tmech.2009.2028422>.
+<a id="orgd8b7cb4"></a>Fleming, A.J. 2010. “Nanopositioning System with Force Feedback for High-Performance Tracking and Vibration Control.” _IEEE/ASME Transactions on Mechatronics_ 15 (3):433–47. <https://doi.org/10.1109/tmech.2009.2028422>.
 
-<a id="org683b96e"></a>Schmidt, R Munnig, Georg Schitter, and Adrian Rankers. 2014. _The Design of High Performance Mechatronics - 2nd Revised Edition_. Ios Press.
+<a id="orga9d9a6b"></a>Schmidt, R Munnig, Georg Schitter, and Adrian Rankers. 2014. _The Design of High Performance Mechatronics - 2nd Revised Edition_. Ios Press.
diff --git a/content/zettels/simulink.md b/content/zettels/simulink.md
index a7b6f81..df53b5c 100644
--- a/content/zettels/simulink.md
+++ b/content/zettels/simulink.md
@@ -4,10 +4,6 @@ author = ["Thomas Dehaeze"]
 draft = false
 +++
 
-Backlinks:
-
--   [Matlab]({{< relref "matlab" >}})
-
 Tags
 : [Matlab]({{< relref "matlab" >}})