diff --git a/content/zettels/transconductance_amplifiers.md b/content/zettels/transconductance_amplifiers.md
index cb3c6a3..a749d3f 100644
--- a/content/zettels/transconductance_amplifiers.md
+++ b/content/zettels/transconductance_amplifiers.md
@@ -56,7 +56,7 @@ Such amplifier is used to control motors (e.g. voice coil, BLDC, stepper motors,
 
 ## Required properties {#required-properties}
 
-Main required properties are (taken from (<a href="#citeproc_bib_item_1">Schmidt, Schitter, and Rankers 2020</a>)):
+Main required properties are (taken from <schmidt20_desig_high_perfor_mechat_third_revis_edition>):
 
 -   **Power delivery capability**
 -   **Dynamic properties**
@@ -206,6 +206,11 @@ W_stop = 0.0025 [W]
 ```
 
 
+## Basic Circuits {#basic-circuits}
+
+<&okyay16_mechat_desig_dynam_contr_metrol>, Appendix A
+
+
 ## Estimation of the required current noise {#estimation-of-the-required-current-noise}
 
 
@@ -318,6 +323,4 @@ In = 2.4e-06 [A/sqrt(Hz)]
 
 ## 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>Schmidt, R Munnig, Georg Schitter, and Adrian Rankers. 2020. <i>The Design of High Performance Mechatronics - Third Revised Edition</i>. Ios Press.</div>
-</div>
+<./biblio/references.bib>