docs: generated systems linked from other documentation chapters

Author: mpusz

docs/users_guide/systems/cgs.md

@@ -257,6 +257,8 @@ For general engineering and most modern scientific work, [SI units](si.md) are r
 
 ## References
 
-- [CGS Units on Wikipedia](https://en.wikipedia.org/wiki/Centimetre%E2%80%93gram%E2%80%93second_system_of_units)
-- [International System of Units (SI)](si.md)
+- [CGS Systems Reference](../../reference/systems_reference/systems/cgs.md) - Complete
+  list of units
 - [Systems of Units](../framework_basics/systems_of_units.md) - Framework basics
+- [International System of Units (SI)](si.md)
+- [CGS Units on Wikipedia](https://en.wikipedia.org/wiki/Centimetre%E2%80%93gram%E2%80%93second_system_of_units)

docs/users_guide/systems/iau.md

@@ -15,12 +15,23 @@ The **mp-units** IAU system implements:
 - **CODATA 2018**: Measured values for the Newtonian gravitational constant G and derived
   _masses_
 
-!!! tip "When to Use"
+!!! tip "Astronomy Utilities"
 
-    - Use **`iau`** for professional astronomy/astrophysics calculations requiring IAU standard values
-    - Use **`astronomy`** utilities (see tip at the end) for common astronomy units like light-years,
-      jansky, or sidereal days
-    - The two can be used together when needed
+    For commonly used astronomy units not standardized by the IAU (such as light-years,
+    jansky, sidereal days, Julian years, etc.), see the `astronomy` utility system:
+
+    ```cpp
+    #include <mp-units/systems/astronomy.h>
+
+    using namespace mp_units::astronomy::unit_symbols;
+
+    quantity distance = 4.22 * ly;        // light-year
+    quantity flux = 1.5 * Jy;             // jansky (radio astronomy)
+    quantity period = 1. * D_sid;         // sidereal day
+    quantity age = 13.8e9 * a;            // Julian year
+    ```
+
+    These units can be freely mixed with IAU and SI units.
 
 ## Resolution B3: Nominal Values
 
@@ -289,27 +300,13 @@ Exoplanet mass: 0.13 M_⊕
 
 ## References
 
-- [IAU Resolution B3 (2015)](https://www.iau.org/Iau/Publications/List-of-Resolutions) -
+- [IAU Systems Reference](../../reference/systems_reference/systems/iau.md) - Complete
+  list of IAU units
+- [Astronomy Systems Reference](../../reference/systems_reference/systems/astronomy.md) -
+  Complete list of astronomy utility units
+- [IAU 2015 Resolution B3](https://www.iau.org/Iau/Publications/List-of-Resolutions) -
   Nominal conversion constants for selected solar and planetary properties
-- [IAU Resolution B2 (2012)](https://www.iau.org/Iau/Publications/List-of-Resolutions) -
+- [IAU 2012 Resolution B2](https://www.iau.org/Iau/Publications/List-of-Resolutions) -
   On the re-definition of the astronomical unit of length
 - [CODATA 2018](https://physics.nist.gov/cuu/Constants/index.html) -
   Internationally recommended values of the fundamental physical constants
-
-!!! tip "Astronomy Utilities"
-
-    For commonly used astronomy units not standardized by the IAU (such as light-years,
-    jansky, sidereal days, Julian years, etc.), see the `astronomy` utility system:
-
-    ```cpp
-    #include <mp-units/systems/astronomy.h>
-
-    using namespace mp_units::astronomy::unit_symbols;
-
-    quantity distance = 4.22 * ly;        // light-year
-    quantity flux = 1.5 * Jy;             // jansky (radio astronomy)
-    quantity period = 1. * D_sid;         // sidereal day
-    quantity age = 13.8e9 * a;            // Julian year
-    ```
-
-    These units can be freely mixed with IAU and SI units.

docs/users_guide/systems/isq.md

@@ -5,15 +5,15 @@
 The **International System of Quantities (ISQ)** is the system of quantities used as the basis
 for the International System of Units (SI) and other systems of units.
 
-The ISQ is defined across the ISO/IEC 80000 series, which currently includes parts 1-17
-covering quantities and units in various domains.
-
 !!! info
 
     For a general introduction to systems of quantities and their importance, see
     [Systems of Quantities](../framework_basics/systems_of_quantities.md) in the
     Framework Basics section.
 
+The ISQ is defined across the ISO/IEC 80000 series, which currently includes parts 1-17
+covering quantities and units in various domains.
+
 **mp-units** provides comprehensive support for the ISQ, likely making it the first
 library (in any programming language) to model the complete ISO/IEC 80000 quantity
 specification.
@@ -252,7 +252,9 @@ both are lengths.
 
 ## References
 
-- [ISO/IEC 80000 series](https://www.iso.org/standard/76921.html)
-- [SI Brochure (9th edition)](https://www.bipm.org/en/publications/si-brochure)
+- [ISQ Systems Reference](../../reference/systems_reference/systems/isq.md) - Complete
+  list of quantities, dimensions, and hierarchies
 - [Systems of Quantities](../framework_basics/systems_of_quantities.md) - Framework basics
 - [Systems of Units](../framework_basics/systems_of_units.md) - Framework basics
+- [ISO/IEC 80000 series](https://www.iso.org/standard/76921.html)
+- [SI Brochure (9th edition)](https://www.bipm.org/en/publications/si-brochure)

docs/users_guide/systems/si.md

@@ -322,6 +322,8 @@ std::cout << kinetic_energy.in(J) << "\n";        // Energy in joules
 
 ## References
 
+- [SI Systems Reference](../../reference/systems_reference/systems/si.md) - Complete
+  list of units, prefixes, and point origins
+- [Systems of Units](../framework_basics/systems_of_units.md) - Framework basics
 - [SI Brochure (9th edition)](https://www.bipm.org/en/publications/si-brochure)
 - [International System of Quantities (ISQ)](isq.md)
-- [Systems of Units](../framework_basics/systems_of_units.md) - Framework basics

docs/users_guide/systems/strong_angular_system.md

@@ -175,3 +175,11 @@ Applying a perpendicular force of 500 N to a 20 cm long lever results in 100 N m
     You can find more information about this constant in [Quincey](../../reference/bibliography.md#Quincey).
 
 [Try it live on Compiler Explorer](https://godbolt.org/z/qfxosv9YM){ .md-button }
+
+## References
+
+<!-- markdownlint-disable MD013 -->
+- [Angular Systems Reference](../../reference/systems_reference/systems/angular.md) - Complete list of quantities and units
+- [ISQ Angle Systems Reference](../../reference/systems_reference/systems/isq_angle.md) - ISQ with strong angular dimensions
+- [Quincey: Angles in the SI](../../reference/bibliography.md#Quincey) - Detailed proposal for solving the angle problem
+<!-- markdownlint-enable MD013 -->

docs/users_guide/systems/yard_pound.md

@@ -468,6 +468,11 @@ quantity land_area = 1 * usc::acre;  // Acre is based on survey chains
 
 ## Further Reading
 
+<!-- markdownlint-disable MD013 -->
+- [Yard-Pound Systems Reference](../../reference/systems_reference/systems/yard_pound.md) - Complete list of yard_pound units
+- [Imperial Systems Reference](../../reference/systems_reference/systems/imperial.md) - Complete list of imperial units
+- [USC Systems Reference](../../reference/systems_reference/systems/usc.md) - Complete list of US customary units
 - [The International Yard and Pound Agreement (1959)](https://www.ngs.noaa.gov/PUBS_LIB/FedRegister/FRdoc59-5442.pdf)
 - [United Kingdom Weights and Measures Act (1985)](https://www.legislation.gov.uk/ukpga/1985/72)
 - [NIST Special Publication 811: Guide for the Use of the International System of Units](https://www.nist.gov/pml/special-publication-811)
+<!-- markdownlint-enable MD013 -->