Make sure that only videos from the same channel are recommended.

src/2_coordinates.md

@@ -13,7 +13,7 @@ The lecture on coordinate systems consists of 3 parts, each with their own video
 
 ## Introduction to coordinate systems: Cartesian and polar
 
-<iframe width="100%" height=315 src="https://www.youtube-nocookie.com/embed/CPMrsQlNxS8" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+<iframe width="100%" height=315 src="https://www.youtube-nocookie.com/embed/CPMrsQlNxS8?rel=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
 ### Cartesian coordinates
 
@@ -154,7 +154,7 @@ understood: the area swept by an angle difference $d\varphi$
 
 ## Converting derivatives between coordinate systems
 
-<iframe width="100%" height=315 src="https://www.youtube-nocookie.com/embed/NGQWGx71w98" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+<iframe width="100%" height=315 src="https://www.youtube-nocookie.com/embed/NGQWGx71w98?rel=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
 
 Often, in physics important equations involve derivatives given in terms
@@ -224,7 +224,7 @@ it's usually best to look up the correct form.
 
 ## Coordinate systems in 3D
 
-<iframe width="100%" height=315 src="https://www.youtube-nocookie.com/embed/VjUbnZN1BvA" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+<iframe width="100%" height=315 src="https://www.youtube-nocookie.com/embed/VjUbnZN1BvA?rel=0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
 
 ### Cylindrical coordinates