Update textbook.en.md

12.temporary_ins/05.coordinates-systems/30.cylindrical-coordinates/10.main/textbook.en.md

@@ -45,7 +45,7 @@ $`\def\PSclosed{\mathscr{S}_{\displaystyle\tiny\bigcirc}}`$
 
 ! For example, this course element denoted * CS300 *:
 
-* * CS300 *:
+* *CS300* :
 
 Reference frame: Cartesian coordinate system $`(O, x, y, z)`$
 \ - **1 point $`O`$ origin** of the space. <br>
@@ -61,7 +61,7 @@ The cylindrical coordinates are defined from a Cartesian coordinate system, i.e.
 
 ! The following element * CS310 *:
 
-* * CS310 *:
+* *CS310* :
 
 Cylindrical coordinates $`(\rho,\varphi,z)`$: