Added "Implementing Functional Languages: A Tutorial"

free-programming-books.md

@@ -253,6 +253,7 @@
 * [Compiler Construction](http://www.ethoberon.ethz.ch/WirthPubl/CBEAll.pdf) (PDF)
 * [Compiler Design: Theory, Tools, and Examples, C/C++ Edition](http://elvis.rowan.edu/~bergmann/books/c_cpp/) -  Seth D. Bergmann
 * [Compiler Design: Theory, Tools, and Examples, Java Edition](http://elvis.rowan.edu/~bergmann/books/java/) -  Seth D. Bergmann
+* [Implementing Functional Languages: A Tutorial](http://research.microsoft.com/en-us/um/people/simonpj/Papers/pj-lester-book/) - Simon Peyton Jones, David Lester
 * [Let's Build a Compiler](http://www.stack.nl/~marcov/compiler.pdf) (PDF)
 * [Linkers and loaders](http://www.iecc.com/linker/)
 * [Practical and Theoretical Aspects of Compiler Construction](http://www.stanford.edu/class/archive/cs/cs143/cs143.1128/) (class lectures and slides)