DOCSP-33263 update learn more (#5322)

Author: jocelyn-mendez1

source/tutorial/equality-sort-range-rule.txt

@@ -157,16 +157,11 @@ Following the ESR rule, the optimal index for the example query is:
 
    { manufacturer: 1, model: 1, cost: 1 }
 
-Further Discussion
-------------------
+Learn More
+----------
 
-A number of MongoDB conference presentations discuss the ESR rule in
-depth.
+- :ref:`create-indexes-to-support-queries`
 
-- `Tips and Tricks for Effective Indexing
-  <https://www.slideshare.net/mongodb/mongodb-local-toronto-2019-tips-and-tricks-for-effective-indexing>`__
-- `The Sights (and Smells) of a Bad Query
-  <https://www.slideshare.net/mongodb/mongodb-world-2019-the-sights-and-smells-of-a-bad-query>`__
-- `Tips and Tricks++ for Querying and Indexing MongoDB
-  <https://www.slideshare.net/mongodb/mongodb-world-2019-tips-and-tricks-for-querying-and-indexing-mongodb>`__
+- :ref:`index-sort`
 
+- :ref:`index-selectivity`