diff --git a/core/core.api.php b/core/core.api.php
index 802252b..eb16ee0 100644
--- a/core/core.api.php
+++ b/core/core.api.php
@@ -1128,7 +1128,7 @@
  * can click links, visit URLs, post to forms, etc. To write a functional test:
  * - Extend \Drupal\Tests\BrowserTestBase.
  * - Place the test in the yourmodule/tests/src/Functional/ directory and use
- *   the Drupal\Tests\yourmodule\Functional\ namespace.
+ *   the \Drupal\Tests\yourmodule\Functional namespace.
  * - Add a @group annotation. For example, if the test is for a Drupal 6
  *   migration process, the group core uses is migrate_drupal_6. Use yourmodule
  *   as the group name if the test does not belong to another larger group.
@@ -1145,12 +1145,14 @@
  * For more details, see:
  * - https://www.drupal.org/docs/8/phpunit/phpunit-browser-test-tutorial for
  *   a full tutorial on how to write functional PHPUnit tests for Drupal.
+ * - https://www.drupal.org/phpunit for the full documentation on how to write
+ *   PHPUnit tests for Drupal.
  *
  * @section write_jsfunctional_phpunit Write functional JavaScript tests (phpunit)
  * To write a functional test that relies on JavaScript:
  * - Extend \Drupal\FunctionalJavaScriptTests\JavascriptTestBase.
  * - Place the test into the yourmodule/tests/src/FunctionalJavascript/
- *   directory and use the Drupal\Tests\yourmodule\FunctionalJavascript\
+ *   directory and use the \Drupal\Tests\yourmodule\FunctionalJavascript
  *   namespace.
  * - Add a @group annotation. Use yourmodule as the group name if the test does
  *   not belong to another larger group.
@@ -1160,6 +1162,11 @@
  *   the underlying browser might take time to deliver changes to the HTML. Use
  *   $this->assertSession()->assertWaitOnAjaxRequest() to wait for the Ajax
  *   request to finish.
+ * For more details, see:
+ * - https://www.drupal.org/docs/8/phpunit/phpunit-javascript-testing-tutorial
+ *   for a full tutorial on how to write PHPUnit JavaScript tests for Drupal.
+ * - https://www.drupal.org/phpunit for the full documentation on how to write
+ *   PHPUnit tests for Drupal.
  *
  * @section running Running tests
  * You can run both Simpletest and PHPUnit tests by enabling the core Testing