Fix wrongly indented bullet point

Just a small typo/error I found while reading through the list.

free-programming-books.md

@@ -283,7 +283,8 @@ Original Source: [List of freely available programming books](http://web.archive
 * [Matters Computational: Ideas, Algorithms, Source Code](http://www.jjj.de/fxt/fxtbook.pdf) (PDF)
 * [Open Data Structures: An Introduction](http://www.aupress.ca/index.php/books/120226) - 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)* [Purely Functional Data Structures](http://www.cs.cmu.edu/~rwh/theses/okasaki.pdf) (PDF)
+* [Problems on Algorithms (Second Edition)](https://larc.unt.edu/ian/books/free/license.html) - Ian Parberry (use form at bottom of license)
+* [Purely Functional Data Structures](http://www.cs.cmu.edu/~rwh/theses/okasaki.pdf) (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)
 * [The Algorithm Design Manual](http://www8.cs.umu.se/kurser/TDBAfl/VT06/algorithms/BOOK/BOOK/BOOK.HTM)