add refs

Author: zingale

Docs/source/comprehensive_tests.rst

@@ -1,3 +1,5 @@
+.. _sec:comprehensive_tests:
+
 ************************
 Comprehensive Unit Tests
 ************************

Docs/source/one_zone_tests.rst

@@ -1,3 +1,5 @@
+.. _sec:one_zone_tests:
+
 **************
 One Zone Tests
 **************

Docs/source/unit_test_runtime_parameters.rst

@@ -25,7 +25,7 @@ Most of the unit tests require a composition to be defined (for the
 initial mass-fractions, $X_k$).  There are a few ways this can be done
 (depending on the test).
 
-* One-zone (``*_cell``) tests usually do one of:
+* One-zone (``*_cell``) tests (see :ref:`sec:one_zone_tests`) usually do one of:
 
   * *Explicitly setting the individual mass fractions.*  This is
     controlled by the parameters ``unit_test.X1``, ``unit_test.X2``, ..., ``unit_test.X35``,
@@ -45,7 +45,7 @@ initial mass-fractions, $X_k$).  There are a few ways this can be done
     ``unit_test.uniform_xn``.  If this is set to ``1``, then each mass fraction
     is initialized to ``1 / NumSpec``.
 
-* Comprehensive tests need many different compositions, since they are creating a cube
+* Comprehensive tests (see :ref:`sec:comprehensive_tests`) need many different compositions, since they are creating a cube
   of varying thermodynamic properties, and thus require a prescription
   to create the composition.  This is done by setting ``unit_test.primary_species_1``,
   ``unit_test.primary_species_2``, and ``unit_test.primary_species_3`` to one of the