diff --git a/content/zettels/system_identification.md b/content/zettels/system_identification.md
index de1750f..c84eeb8 100644
--- a/content/zettels/system_identification.md
+++ b/content/zettels/system_identification.md
@@ -96,7 +96,7 @@ At high frequency, the measurement noise dominates and the coherence is poor.
 ### Closed-Loop identification {#closed-loop-identification}
 
 If the open-loop system is unstable, a first simple controller needs to be designed to stabilizes the system.
-Then, the plant can be identified from closed-loop system identification ([Figure 5](#figure--fig:siso-identification-schematic-simplier-closed-loop)).
+Then, the plant can be identified from closed-loop system identification ([Figure 6](#figure--fig:siso-identification-schematic-simplier-closed-loop)).
 
 <a id="figure--fig:siso-identification-schematic-simplier-closed-loop"></a>
 
@@ -131,7 +131,7 @@ T = 1 - S;
 
 ### Multi-Input Multi-Output Plant {#multi-input-multi-output-plant}
 
-This can be generalized to a MIMO plant ([Figure 5](#figure--fig:siso-identification-schematic-simplier-closed-loop)).
+This can be generalized to a MIMO plant ([Figure 6](#figure--fig:siso-identification-schematic-simplier-closed-loop)).
 
 <a id="figure--fig:siso-identification-schematic-simplier-closed-loop"></a>
 
@@ -431,7 +431,7 @@ end
 ## 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>Pintelon, Rik, and Johan Schoukens. 2012. <i>System Identification : a Frequency Domain Approach</i>. Hoboken, N.J. Piscataway, NJ: Wiley IEEE Press. doi:<a href="https://doi.org/10.1002/9781118287422">10.1002/9781118287422</a>.</div>
+  <div class="csl-entry"><a id="citeproc_bib_item_1"></a>Pintelon, R., and J. Schoukens. 2012. <i>System Identification : a Frequency Domain Approach</i>. Hoboken, N.J. Piscataway, NJ: Wiley IEEE Press. doi:<a href="https://doi.org/10.1002/9781118287422">10.1002/9781118287422</a>.</div>
   <div class="csl-entry"><a id="citeproc_bib_item_2"></a>Schoukens, Johan, Rik Pintelon, and Yves Rolain. 2012. <i>Mastering System Identification in 100 Exercises</i>. John Wiley &#38; Sons.</div>
   <div class="csl-entry"><a id="citeproc_bib_item_3"></a>Schroeder, Manfred. 1970. “Synthesis of Low-Peak-Factor Signals and Binary Sequences with Low Autocorrelation (Corresp.).” <i>IEEE Transactions on Information Theory</i> 16 (1). IEEE: 85–89.</div>
 </div>