diff --git a/books/free-programming-books-langs.md b/books/free-programming-books-langs.md
index 9373656ce..98c0a3992 100644
--- a/books/free-programming-books-langs.md
+++ b/books/free-programming-books-langs.md
@@ -1588,13 +1588,14 @@ Books on general-purpose programming that don't focus on a specific language are
 * [Learn Markdown](https://www.gitbook.com/book/gitbookio/markdown/details) - Sammy P., Aaron O. (PDF) (EPUB) (MOBI)
 
 
-### Mathematica
+### Mathematical
 
 * [Mathematica® programming: an advanced introduction](http://www.mathprogramming-intro.org) - Leonid Shifrin
 * [Power Programming with Mathematica](http://mathematica.stackexchange.com/questions/16485/are-you-interested-in-purchasing-david-wagners-power-programming-with-mathemat/22724) - David B. Wagner
 * [Stephen Wolfram's The Mathematica Book](http://reference.wolfram.com/legacy/v5_2/)
 * [Vector Math for 3d Computer Graphics](http://chortle.ccsu.edu/VectorLessons/index.html) (CC BY-NC)
 * [Wolfram Mathematica Product Training: Wolfram U](https://www.wolfram.com/wolfram-u/catalog/product-training/mathematica/)
+* [Practical Statistics](https://github.com/Chandra0505/Data-Science-Resources/blob/master/machine-learning/Practical%20Statistics%20for%20Data%20Scientists.pdf) -Andrew Bruce, Peter Bruce, and Peter Gedeck
 
 
 ### MATLAB
diff --git a/courses/free-courses-en.md b/courses/free-courses-en.md
index 6065ba3bf..5250aad5e 100644
--- a/courses/free-courses-en.md
+++ b/courses/free-courses-en.md
@@ -526,6 +526,7 @@
 
 * [Advanced Data Mining with Weka MOOC](https://www.cs.waikato.ac.nz/ml/weka/mooc/advanceddataminingwithweka/)
 * [An Introduction to Data Science](https://www.udemy.com/course/an-introduction-to-data-science/)
+* [Practical Statistics for Data Science](https://github.com/Chandra0505/Data-Science-Resources/blob/master/machine-learning/Practical%20Statistics%20for%20Data%20Scientists.pdf) -Andrew Bruce, Peter Bruce, and Peter Gedeck
 * [Apache Airflow Tutorials](https://www.youtube.com/playlist?list=PLYizQ5FvN6pvIOcOd6dFZu3lQqc6zBGp2) - Tuan Vu
 * [Applied Data Science with Python](https://cognitiveclass.ai/learn/data-science-with-python) - CognitiveClass.ai
 * [Big Data Engineering Course](https://www.youtube.com/playlist?list=PLLa_h7BriLH2UYJIO9oDoP3W-b6gQeA12) - Data Engineering
diff --git a/more/free-programming-cheatsheets.md b/more/free-programming-cheatsheets.md
index 603ca4bfd..6cd0aa738 100644
--- a/more/free-programming-cheatsheets.md
+++ b/more/free-programming-cheatsheets.md
@@ -11,6 +11,8 @@
 * [Dart](#dart)
 * [Data Science](#data-science)
 * [Data Structures and Algorithms](#data-structures-and-algorithms)
+* [Data Base And Management System](#data-base-and-management-system)
+* [DBMS] (#data-structures-and-algorithms)
 * [Docker](#docker)
 * [Git](#git)
 * [Go](#go)
@@ -143,6 +145,9 @@
 * [Data Structures and Algorithms Cheat Sheet - Cheatography](https://cheatography.com/burcuco/cheat-sheets/data-structures-and-algorithms/)
 * [Data structures and algorithms study cheatsheets for coding interviews](https://www.techinterviewhandbook.org/algorithms/study-cheatsheet/)
 
+### Data Base And Management System
+
+* [DBMS Cheat Sheet](https://www.tutorialspoint.com/dbms/pdf/dbms_quick_guide.pdf) - DBMS
 
 ### Docker