diff --git a/free-programming-books.md b/free-programming-books.md
index fb5db98bb..fea53eba3 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -310,14 +310,14 @@
 * [Elementary Algorithms](https://github.com/liuxinyu95/AlgoXY) - Larry LIU Xinyu
 * [Foundations of Computer Science](http://infolab.stanford.edu/~ullman/focs.html) - Al Aho and Jeff Ullman
 * [Geometry Algorithms](http://geomalgorithms.com) - Dan Sunday
-* [Lectures Notes on Algorithm Analysis and Computational Complexity (Fourth Edition)](https://larc.unt.edu/ian/books/free/license.html) - Ian Parberry (use form at bottom of license)
+* [Lectures Notes on Algorithm Analysis and Computational Complexity (Fourth Edition)](http://ianparberry.com/books/free/license.html) - Ian Parberry (use form at bottom of license)
 * [LEDA: A Platform for Combinatorial and Geometric Computing](http://people.mpi-inf.mpg.de/~mehlhorn/LEDAbook.html) - K. Mehlhorn et al.
 * [Linked List Basics](http://cslibrary.stanford.edu/103/LinkedListBasics.pdf) (PDF)
 * [Linked List Problems](http://cslibrary.stanford.edu/105/LinkedListProblems.pdf) (PDF)
 * [Matters Computational: Ideas, Algorithms, Source Code](http://www.jjj.de/fxt/fxtbook.pdf) (PDF)
 * [Open Data Structures: An Introduction](http://opendatastructures.org) - Pat Morin
 * [Planning Algorithms](http://planning.cs.uiuc.edu)
-* [Problems on Algorithms (Second Edition)](https://larc.unt.edu/ian/books/free/license.html) - Ian Parberry (use form at bottom of license)
+* [Problems on Algorithms (Second Edition)](http://ianparberry.com/books/free/license.html) - Ian Parberry (use form at bottom of license)
 * [Purely Functional Data Structures (1996)](http://www.cs.cmu.edu/~rwh/theses/okasaki.pdf) - Chris Okasaki (PDF)
 * [Sequential and parallel sorting algorithms](http://www.inf.fh-flensburg.de/lang/algorithmen/sortieren/algoen.htm)
 * [Text Algorithms](http://igm.univ-mlv.fr/~mac/REC/text-algorithms.pdf) (PDF)