diff --git a/books/free-programming-books-subjects.md b/books/free-programming-books-subjects.md
index 08f79c86e..184e59e3c 100644
--- a/books/free-programming-books-subjects.md
+++ b/books/free-programming-books-subjects.md
@@ -559,6 +559,7 @@ Books that cover a specific programming language can be found in the [BY PROGRAM
 * [Probability and Statistics Cookbook](http://statistics.zone)
 * [Probability and Statistics EBook](http://wiki.stat.ucla.edu/socr/index.php/Probability_and_statistics_EBook)
 * [Probability: Lectures and Labs](https://www.markhuberdatascience.org/probability-textbook) - Mark Huber
+* [Proofs and Types](https://www.paultaylor.eu/stable/Proofs+Types) - Jean-Yves Girard, Yves Lafont, Paul Taylor
 * [Recreations in Math](http://djm.cc/library/Recreations_in_Mathematics_Licks_edited.pdf) - H. E. Licks (PDF)
 * [Sage for Undergraduates](http://www.gregorybard.com/books.html) - Gregory Bard
 * [Second Course in Algebra](http://djm.cc/library/Second_Algebra_Hawkes_Luby_Touton_edited.pdf) - Herbert E. Hawkes, William A. Luby, Frank C. Touton (PDF)