diff --git a/free-programming-books-de.md b/free-programming-books-de.md
index 1080b2b21..0cff17b41 100644
--- a/free-programming-books-de.md
+++ b/free-programming-books-de.md
@@ -89,7 +89,6 @@
 * [EJB 3 für Umsteiger: Neuerungen und Änderungen gegenüber dem EJB-2.x-Standard](http://bsd.de/e3fu/umfrage.html) - Heiko W. Rupp
 * [Java 7 Mehr als eine Insel](http://openbook.galileocomputing.de/java7/)
 * [Java ist auch eine Insel](http://openbook.galileocomputing.de/javainsel/)
-* [JSFAtWork, JSF 2.0 und Apache MyFaces](http://jsfatwork.irian.at/book_de/)
 * [Programmieren Java: Einführung](http://www.highscore.de/java/einfuehrung/)
 * [Programmieren Java: Aufbau](http://www.highscore.de/java/aufbau/)
 
diff --git a/free-programming-books-fr.md b/free-programming-books-fr.md
index cadc282fe..36012475a 100644
--- a/free-programming-books-fr.md
+++ b/free-programming-books-fr.md
@@ -6,7 +6,6 @@
     * [Logiciels libres](#logiciels-libres)
     * [Makefile](#makefile)
     * [Méthodes de développment](#méthodes-de-développement)
-    * [Systèmes informatiques](#systèmes-informatiques)
     * [Théorie des langages](#théorie-des-langages)
 * [Assembleur](#assembleur)
 * [Bash / Shell](#bash--shell)
@@ -68,10 +67,6 @@
 * [Scrum et XP depuis les tranchées](http://www.infoq.com/resource/news/2007/06/scrum-xp-book/en/resources/ScrumAndXpFromTheTrenches_French.pdf), par Henrik Kniberg
 
 
-####Systèmes Informatiques
-* [Systèmes Informatiques (C, Unix/Linux,...)](http://sinf1252.info.ucl.ac.be/), par Olivier Bonaventure ([sources](https://github.com/obonaventure/SystemesInformatiques))
-
-
 ####Théorie des langages
 * [Compilation. Théorie des langages](http://www.lisyc.univ-brest.fr/pages_perso/leparc/Etud/Master/Compil/Doc/CoursCompilation.pdf) par Université de Bretagne Occidentale
 
diff --git a/free-programming-books-id.md b/free-programming-books-id.md
index 0b5a188dc..213fc46cf 100644
--- a/free-programming-books-id.md
+++ b/free-programming-books-id.md
@@ -1,13 +1,9 @@
 ###Index
 
-* [JAVA](#java)
 * [HTML & CSS](#html-css)
 * [Javascript](#javascript)
 * [PHP](#php)
 
-###java
-* [JENI Programming](http://www.taryo.net/free-e-book-pemrograman-java-edisi-indonesia-lengkap.html)
-
 ###html-css
 * [Belajar HTML dan CSS](http://www.ariona.net/ebook-belajar-html-dan-css/)
 
diff --git a/free-programming-books.md b/free-programming-books.md
index 68a6e1727..acf773b83 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -313,7 +313,6 @@
 * [Machine Learning, Neural and Statistical Classification](http://www1.maths.leeds.ac.uk/~charles/statlog/whole.pdf) (PDF) or [online version](http://www1.maths.leeds.ac.uk/~charles/statlog/) - This book is based on the EC (ESPRIT) project StatLog.
 * [Neural Networks and Deep Learning](http://neuralnetworksanddeeplearning.com)
 * [Probabilistic Models in the Study of Language](http://idiom.ucsd.edu/~rlevy/pmsl_textbook/text.html) (Draft, with R code)
-* [Programming Computer Vision with Python](http://programmingcomputervision.com/)
 * [Reinforcement Learning: An Introduction](http://webdocs.cs.ualberta.ca/~sutton/book/ebook/the-book.html)
 * [The Elements of Statistical Learning](http://www-stat.stanford.edu/~tibs/ElemStatLearn/) - Trevor Hastie, Robert Tibshirani, and Jerome Friedman
 * [The Python Game Book](http://thepythongamebook.com/en:start)
@@ -326,11 +325,9 @@
 
 ####Mathematics
 * [A First Course in Linear Algebra](http://linear.ups.edu/) - Robert A. Beezer
-* [Advanced Data Analysis from an Elementary Point of View](http://www.stat.cmu.edu/~cshalizi/ADAfaEPoV/)
 * [Bayesian Methods for Hackers](https://github.com/CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers) - Cameron Davidson-Pilon
 * [CK-12 Probability and Statistics - Advanced](http://www.ck12.org/book/Probability-and-Statistics---Advanced-%2528Second-Edition%2529/)
 * [Calculus Made Easy](http://www.gutenberg.org/ebooks/33283) (PDF) - Silvanus P. Thompson
-* [Category Theory for Computing Science](http://www.math.mcgill.ca/triples/Barr-Wells-ctcs.pdf) (PDF)
 * [Collaborative Statistics](http://cnx.org/content/col10522/latest/)
 * [Concepts & Applications of Inferential Statistics](http://vassarstats.net/textbook/)
 * [Essentials of Metaheuristics](http://cs.gmu.edu/~sean/book/metaheuristics/) by Sean Luke
diff --git a/javascript-frameworks-resources.md b/javascript-frameworks-resources.md
index de7509c9c..6da287996 100644
--- a/javascript-frameworks-resources.md
+++ b/javascript-frameworks-resources.md
@@ -11,7 +11,7 @@
 * [egghead.io: Learn AngularJS with Tutorial Videos & Training](http://egghead.io)
 * [egghead.io youtube channel: Learn AngularJS with Tutorial Videos & Training](https://www.youtube.com/user/johnlindquist)
 * [Mastering AngularJS Directives](http://pascalprecht.github.com/slides/mastering-angularjs-directives/)
-* [Seven-Part Introduction to Angular](http://ngokevin/blog/angular-1)
+* [Seven-Part Introduction to Angular](http://ngokevin.com/blog/angular-1)
 * [Unit Testing Best Practices in AngularJS](http://andyshora.com/unit-testing-best-practices-angularjs.html)