Update content/learn/02.microcontrollers/05.5v-3v3/5v-3v3-guide.md

Co-authored-by: Karl Söderby <[email protected]>

Author: TaddyHC

content/learn/02.microcontrollers/05.5v-3v3/5v-3v3-guide.md

@@ -132,6 +132,6 @@ Handling different voltage levels covers vast electronic department, and without
 
 ## References
 
-[1] Larsson, E. (2006). Introduction to Advanced System-on-Chip Test Design and Optimization. Springer Publishing.<br />
-[2] Kularatna, N. (2018). DC Power Supplies Power Management and Surge Protection for Power Electronic Systems. Amsterdam University Press.<br />
-[3] Ballan, H., & Declercq, M. (2010). High Voltage Devices and Circuits in Standard CMOS Technologies. Springer Publishing.
+- [1] Larsson, E. (2006). Introduction to Advanced System-on-Chip Test Design and Optimization. Springer Publishing.
+- [2] Kularatna, N. (2018). DC Power Supplies Power Management and Surge Protection for Power Electronic Systems. Amsterdam University Press.
+- [3] Ballan, H., & Declercq, M. (2010). High Voltage Devices and Circuits in Standard CMOS Technologies. Springer Publishing.