diff -up ./doc/advanced/content/conf.py.sphinx ./doc/advanced/content/conf.py
--- ./doc/advanced/content/conf.py.sphinx	2020-05-11 04:59:26.000000000 -0400
+++ ./doc/advanced/content/conf.py	2020-06-07 16:11:04.398144850 -0400
@@ -4,7 +4,7 @@
 # -- General configuration -----------------------------------------------------
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.imgmath', 'sphinxcontrib.doxylink.doxylink']
+extensions = ['sphinx.ext.imgmath']
 
 # Add any paths that contain templates here, relative to this directory.
 # templates_path = ['_templates']
@@ -69,7 +69,7 @@ pygments_style = 'sphinx'
 
 # The theme to use for HTML and HTML Help pages.  Major themes that come with
 # Sphinx are currently 'default' and 'sphinxdoc'.
-html_theme = 'sphinx_rtd_theme'
+html_theme = 'sphinxdoc'
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
diff -up ./doc/tutorials/content/conf.py.sphinx ./doc/tutorials/content/conf.py
--- ./doc/tutorials/content/conf.py.sphinx	2020-05-11 04:59:26.000000000 -0400
+++ ./doc/tutorials/content/conf.py	2020-06-07 16:10:46.555225064 -0400
@@ -4,7 +4,7 @@
 # -- General configuration -----------------------------------------------------
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.imgmath', 'sphinxcontrib.doxylink.doxylink']
+extensions = ['sphinx.ext.imgmath']
 imgmath_dvipng_args = ['-gamma', '1.5', '-D', '110', '-bg', 'Transparent']
 
 # Add any paths that contain templates here, relative to this directory.
@@ -70,7 +70,7 @@ pygments_style = 'sphinx'
 
 # The theme to use for HTML and HTML Help pages.  Major themes that come with
 # Sphinx are currently 'default' and 'sphinxdoc'.
-html_theme = 'sphinx_rtd_theme'
+html_theme = 'sphinxdoc'
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the