Fixed typo: Structure and Interpretation (#1985)

free-programming-books.md

@@ -1988,7 +1988,7 @@ For resources on Angular, Backbone, D3, Dojo, Ember, Express, jQuery, Knockout,
 * [How to Design Programs](http://htdp.org)
 * [Scheme Tutorial](http://www.cs.hut.fi/Studies/T-93.210/schemetutorial/)
 * [Simply Scheme: Introducing Computer Science](http://www.cs.berkeley.edu/~bh/ss-toc2.html) - B. Harvey, M. Wright
-* [Structure and Interpretion of Computer Programs](https://mitpress.mit.edu/sicp/full-text/book/book.html)
+* [Structure and Interpretation of Computer Programs](https://mitpress.mit.edu/sicp/full-text/book/book.html)
 * [Teach Yourself Scheme in Fixnum Days](http://www.ccs.neu.edu/home/dorai/t-y-scheme/t-y-scheme.html)
 * [The Scheme Programming Language: Edition 3](http://www.scheme.com/tspl3/) - [The Scheme Programming Language: Edition 4](http://www.scheme.com/tspl4/)
 * [Write Yourself a Scheme in 48 Hours](https://en.wikibooks.org/wiki/Write_Yourself_a_Scheme_in_48_Hours)