diff --git a/content/zettels/norms.md b/content/zettels/norms.md
index 2555de7..a3f3765 100644
--- a/content/zettels/norms.md
+++ b/content/zettels/norms.md
@@ -4,7 +4,7 @@ author = ["Thomas Dehaeze"]
 draft = false
 +++
 
-### Backlinks {#backlinks}
+Backlinks:
 
 -   [Multivariable Control]({{< relref "multivariable_control" >}})
 
@@ -13,9 +13,9 @@ Tags
 
 Resources:
 
--   ([Skogestad and Postlethwaite 2007](#org533c8de))
--   ([Toivonen 2002](#orgb393f10))
--   ([Zhang 2011](#org1ea8e81))
+-   ([Skogestad and Postlethwaite 2007](#org140f9cc))
+-   ([Toivonen 2002](#orgc1385a9))
+-   ([Zhang 2011](#org8471dd8))
 
 
 ## \\(\mathcal{H}\_\infty\\) Norm {#mathcal-h-infty--norm}
@@ -27,24 +27,24 @@ Signal
 
 ## \\(\mathcal{H}\_2\\) Norm {#mathcal-h-2--norm}
 
-RMS value
-
 The \\(\mathcal{H}\_2\\) is very useful when combined to [Dynamic Error Budgeting]({{< relref "dynamic_error_budgeting" >}}).
 
-As explained in ([Monkhorst 2004](#org5e40c21)), the \\(\mathcal{H}\_2\\) norm has a stochastic interpretation:
+As explained in ([Monkhorst 2004](#orgafef987)), the \\(\mathcal{H}\_2\\) norm has a stochastic interpretation:
 
 > The squared \\(\mathcal{H}\_2\\) norm can be interpreted as the output variance of a system with zero mean white noise input.
 
+Minimizing the \\(\mathcal{H}\_2\\) norm can be equivalent as minimizing the RMS value of some signals in the system.
+
 
 ## Link between signal and system norms {#link-between-signal-and-system-norms}
 
 
 ## Bibliography {#bibliography}
 
-<a id="org5e40c21"></a>Monkhorst, Wouter. 2004. “Dynamic Error Budgeting, a Design Approach.” Delft University.
+<a id="orgafef987"></a>Monkhorst, Wouter. 2004. “Dynamic Error Budgeting, a Design Approach.” Delft University.
 
-<a id="org533c8de"></a>Skogestad, Sigurd, and Ian Postlethwaite. 2007. _Multivariable Feedback Control: Analysis and Design_. John Wiley.
+<a id="org140f9cc"></a>Skogestad, Sigurd, and Ian Postlethwaite. 2007. _Multivariable Feedback Control: Analysis and Design_. John Wiley.
 
-<a id="orgb393f10"></a>Toivonen, Hannu T. 2002. “Robust Control Methods.” Abo Akademi University.
+<a id="orgc1385a9"></a>Toivonen, Hannu T. 2002. “Robust Control Methods.” Abo Akademi University.
 
-<a id="org1ea8e81"></a>Zhang, Weidong. 2011. _Quantitative Process Control Theory_. CRC Press.
+<a id="org8471dd8"></a>Zhang, Weidong. 2011. _Quantitative Process Control Theory_. CRC Press.