diff --git a/docs/getting_started/introduction.md b/docs/getting_started/introduction.md
index 7efe47cf..b15b54e0 100644
--- a/docs/getting_started/introduction.md
+++ b/docs/getting_started/introduction.md
@@ -72,9 +72,9 @@ To achieve this goal, several techniques are applied:
 [Systems of Units]: ../users_guide/framework_basics/systems_of_units.md
 [Scalar, vector, and tensor quantities]: ../users_guide/framework_basics/character_of_a_quantity.md
 [The affine space]: ../users_guide/framework_basics/the_affine_space.md
-[Different models of the universe (e.g. natural units systems)]: ../users_guide/defining_systems/natural_units.md
+[Different models of the universe (e.g. natural units systems)]: ../users_guide/systems/natural_units.md
 [Strong dimensionless quantities]: ../users_guide/framework_basics/dimensionless_quantities.md
-[Strong angular system]: ../users_guide/defining_systems/strong_angular_system.md
+[Strong angular system]: ../users_guide/systems/strong_angular_system.md
 [Supports any unit's magnitude (huge, small, floating-point)]: ../users_guide/framework_basics/systems_of_units.md#scaled-units
 [Faster-than-lightspeed constants]: ../users_guide/framework_basics/faster_than_lightspeed_constants.md
 [Highly adjustable text-output formatting]: ../users_guide/framework_basics/text_output.md
diff --git a/docs/users_guide/framework_basics/dimensionless_quantities.md b/docs/users_guide/framework_basics/dimensionless_quantities.md
index 16d272f2..3f0aac07 100644
--- a/docs/users_guide/framework_basics/dimensionless_quantities.md
+++ b/docs/users_guide/framework_basics/dimensionless_quantities.md
@@ -184,7 +184,7 @@ that both _angular measure_ and _solid angular measure_ should also be
 
     Many people claim that angle being a dimensionless quantity is a bad idea. There are
     proposals submitted to make an angle a base quantity and `rad` to become a base unit. More on this
-    topic can be found in the ["Strong Angular System" chapter](../defining_systems/strong_angular_system.md).
+    topic can be found in the ["Strong Angular System" chapter](../systems/strong_angular_system.md).
 
 
 ## Nested quantity kinds
diff --git a/docs/users_guide/framework_basics/systems_of_quantities.md b/docs/users_guide/framework_basics/systems_of_quantities.md
index 07660e1d..438de213 100644
--- a/docs/users_guide/framework_basics/systems_of_quantities.md
+++ b/docs/users_guide/framework_basics/systems_of_quantities.md
@@ -214,7 +214,7 @@ For example, here is how the above quantity kind tree can be modeled in the libr
 !!! note
 
     More information on how to define a system of quantities can be found in the
-    ["International System of Quantities (ISQ)"](../defining_systems/isq.md) chapter.
+    ["International System of Quantities (ISQ)"](../systems/isq.md) chapter.
 
 
 ## Comparing, adding, and subtracting quantities