Revert "config"

This reverts commit a82c9ad5.

book/_config.yml

@@ -10,6 +10,8 @@ only_build_toc_files: true
 
 sphinx:
   config:
+    # Bibliography style
+    bibtex_reference_style: author_year
     patch_config:
       disabled-patches: []
     html_show_copyright: false
@@ -28,11 +30,6 @@ sphinx:
       # END REMOVE-FROM-PUBLISH
       launch_buttons:
         thebe: true
-    bibtex_default_style: myapastyle
-    bibtex_reference_style: author_year_round
-  local_extensions:
-    apastyle: _ext/
-    bracket_citation_style: _ext/
   extra_extensions:
     - sphinx_inline_tabs
     - sphinx_grasple