diff --git a/free-programming-books.md b/free-programming-books.md
index 1afad731..0fa988db 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -370,6 +370,7 @@ Original Source: [Free Programming books](http://stackoverflow.com/revisions/392
 * [Computational Geometry](http://web.mit.edu/hyperbook/Patrikalakis-Maekawa-Cho/)
 * [Concepts & Applications of Inferential Statistics](http://vassarstats.net/textbook/)
 * [Differential Equations](http://tutorial.math.lamar.edu/pdf/DE/DE_Complete.pdf) - Paul Dawkins
+* [Discrete Mathematics](http://home.iitk.ac.in/%7Earlal/book/mth202.pdf) (PDF) - Dr. Arbind K Lal, IIT Kanpur
 * [Elementary Differential Equations](http://ramanujan.math.trinity.edu/wtrench/texts/TRENCH_DIFF_EQNS_I.PDF) - William F. Trench
 * [Essentials of Metaheuristics](http://cs.gmu.edu/~sean/book/metaheuristics/) by Sean Luke
 * [Introduction to Probability](http://www.dartmouth.edu/~chance/teaching_aids/books_articles/probability_book/book.html) - Charles M. Grinstead and J. Laurie Snell
@@ -377,8 +378,9 @@ Original Source: [Free Programming books](http://stackoverflow.com/revisions/392
 * [Introduction to Statistical Thought](http://www.math.umass.edu/~lavine/Book/book.html) - Michael Lavine
 * [Kalman and Bayesian Filters in Python](https://github.com/rlabbe/Kalman-and-Bayesian-Filters-in-Python)
 * [Knapsack Problems - Algorithms and Computer Implementations](http://www.or.deis.unibo.it/knapsack.html) - Silvano Martello and Paolo Toth
-* [Lecture Notes of Linear Algebra](http://home.iitk.ac.in/~psraj/mth102/lecture_notes.html) - (PDF)  Dr. P. Shunmugaraj 
+* [Lecture Notes of Linear Algebra](http://home.iitk.ac.in/~psraj/mth102/lecture_notes.html) (PDF) -  Dr. P. Shunmugaraj, IIT Kanpur
 * [Linear Algebra](https://www.math.ucdavis.edu/~linear/linear-guest.pdf)
+* [Linear Algebra](http://home.iitk.ac.in/~arlal/book/nptel/pdf/book_linear.pdf) (PDF) - Dr. Arbind K Lal, IIT Kanpur
 * [Linear Algebra: An Introduction to Mathematical Discourse](http://en.wikibooks.org/wiki/Linear_Algebra) - Jim Hefferon
 * [Linear Algebra, Theory And Applications](http://www.math.byu.edu/klkuttle/linearalgebra.pdf) - Kenneth Kuttler
 * [Mathematical Logic - an Introduction](http://www.ii.uib.no/~michal/und/i227/book/book.pdf) (PDF)