DOCSP-15709: Link to Practical MDB Aggs Book

Author: npentrel

source/aggregation.txt

@@ -139,9 +139,19 @@ For a feature comparison of the aggregation pipeline,
 map-reduce, and the special group functionality, see
 :doc:`/reference/aggregation-commands-comparison`.
 
+Learn More
+----------
+
+Practical MongoDB Aggregations E-Book
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For more information on aggregations, read the `Practical MongoDB
+Aggregations <https://www.practical-mongodb-aggregations.com>`__ e-book.
+
+
 .. toctree::
-   :titlesonly: 
-   :hidden: 
+   :titlesonly:
+   :hidden:
 
    /core/aggregation-pipeline
    /core/map-reduce

source/index.txt

@@ -156,6 +156,9 @@ MongoDB. You can:
 - Download the `Architecture Guide
   <https://www.mongodb.com/lp/whitepaper/architecture-guide?jmp=docs>`_
 
+- Read the `Practical MongoDB Aggregations (e-book)
+  <https://www.practical-mongodb-aggregations.com>`__ e-book
+
 Licensing
 ---------
 

source/reference/aggregation.txt

@@ -37,13 +37,18 @@ Aggregation Reference
       the aggregation pipeline and operators in MongoDB and common SQL
       statements.
 
+`Practical MongoDB Aggregations <https://www.practical-mongodb-aggregations.com>`__
+   For more information on aggregations, read the `Practical MongoDB
+   Aggregations <https://www.practical-mongodb-aggregations.com>`__
+   e-book.
 
 .. toctree::
-   :titlesonly: 
-   :hidden: 
+   :titlesonly:
+   :hidden:
 
    /meta/aggregation-quick-reference
    /reference/operator/aggregation/interface
    /reference/aggregation-commands-comparison
    /reference/aggregation-variables
    /reference/sql-aggregation-comparison
+   Practical MongoDB Aggregations <https://www.practical-mongodb-aggregations.com>