diff --git a/books/free-programming-books-subjects.md b/books/free-programming-books-subjects.md
index 8edb2a60c..226e4eba3 100644
--- a/books/free-programming-books-subjects.md
+++ b/books/free-programming-books-subjects.md
@@ -518,6 +518,7 @@ Books that cover a specific programming language can be found in the  [BY PROGRA
 * [Digital Signal Processing For Engineers and Scientists](http://www.dspguide.com)
 * [Digital Signal Processing in Python](https://greenteapress.com/wp/think-dsp) - Allen B. Downey
 * ["DYNAMIC LINKED LIBRARIES": Paradigms of the GPL license in contemporary software](http://www.lulu.com/shop/http://www.lulu.com/shop/luis-enr%C3%ADquez-a/dynamic-linked-libraries-paradigms-of-the-gpl-license-in-contemporary-software/ebook/product-21419788.html) - Luis A. Enríquez
+* [Encyclopedia of Human Computer Interaction 2nd Edition](https://www.interaction-design.org/literature/book/the-encyclopedia-of-human-computer-interaction-2nd-ed)
 * [Essential Image Optimization](https://images.guide) - Addy Osmani
 * [Foundations of Programming](https://openmymind.net/FoundationsOfProgramming.pdf) - Karl Seguin (PDF)
 * [Getting Real](https://basecamp.com/books/getting-real) - Basecamp, 37signals ([HTML](https://basecamp.com/gettingreal), [PDF](https://basecamp.com/gettingreal/getting-real.pdf))