Merge pull request #623 from alexanderfefelov/master

Added a few books

free-programming-books.md

@@ -439,11 +439,14 @@
 * [Data-Oriented Design](http://www.dataorienteddesign.com/dodmain/dodmain.html)
 * [Domain Driven Design Quickly](http://www.infoq.com/minibooks/domain-driven-design-quickly)
 * [Don't Just Roll the Dice](http://www.neildavidson.com/dontjustrollthedice.html)
+* [DSL Engineering: Designing, Implementing and Using Domain-Specific Languages](http://dslbook.org/) - Markus Voelter
 * [Essential Skills for Agile Development](http://elliottback.com/wp/essential-skills-for-agile-development/)
 * [Guide to the Software Engineering Body of Knowledge](http://www.computer.org/portal/web/swebok)
 * [How to Design Programs](http://www.htdp.org/)
 * [How to Write Unmaintainable Code](http://mindprod.com/jgloss/unmain.html)
 * [Kanban and Scrum - making the most of both](http://www.infoq.com/minibooks/kanban-scrum-minibook)
+* [Methods and Techniques for the Design and Implementation of Domain-Specific Languages](http://www.st.ewi.tudelft.nl/~arie/phds/Hemel.pdf) - Zef Hemel
+* [Naked objects](http://downloads.nakedobjects.net/resources/Pawson%20thesis.pdf) - Richard Pawson
 * [NASA Manager Handbook for Software Development](http://homepages.inf.ed.ac.uk/dts/pm/Papers/nasa-manage.pdf) (PDF)
 * [NASA Software Measurement Handbook](http://www.scribd.com/doc/7181362/NASA-Software-Measurement-Guidebook)
 * [OAuth - The Big Picture](http://pages.apigee.com/oauth-big-picture-ebook.html)
@@ -1201,6 +1204,7 @@ See also [TeX](#tex)
 * [Prolog and Natural-Language Analysis](http://www.mtome.com/Publications/PNLA/pnla-digital.html) - Fernando C. N. Pereira, Stuart M. Shieber
 * [Prolog Experiments in Discrete Mathematics, Logic, and Computability](http://web.cecs.pdx.edu/~jhein/books/PrologLabBook09.pdf) - James L. Hein
 * [Prolog for Programmers](https://sites.google.com/site/prologforprogrammers/)
+* [Prolog Problems](https://sites.google.com/site/prologsite/prolog-problems) - Werner Hett
 * [Prolog Programming: A First Course](http://engronline.ee.memphis.edu/deductiveDB/prolog_book.pdf) - Paul Brna
 * [Prolog Techniques](http://bookboon.com/int/student/it/prolog-techniques-applications-of-prolog)
 * [Simply Logical](http://www.cs.bris.ac.uk/~flach/SimplyLogical.html)
@@ -1360,6 +1364,7 @@ See also [TeX](#tex)
 * [Pro Scala: Monadic Design Patterns for the Web](http://github.com/leithaus/XTrace/tree/monadic/src/main/book/content/)
 * [Program Transformation in Scala](http://homepages.cwi.nl/~ai/MScThesis-A-Izmaylova.pdf) - Anastasia Izmaylova
 * [Programming in Scala, First Edition](http://www.artima.com/pins1ed/)
+* [S-99: Ninety-Nine Scala Problems](http://aperiodic.net/phil/scala/s-99/) - Phil! Gold
 * [Scala By Example](http://www.scala-lang.org/docu/files/ScalaByExample.pdf) (PDF)
 * [Scala Cookbook: Bonus Chapters](http://examples.oreilly.com/9781449339616-files/Scala_Cookbook_bonus_chapters.pdf) - Alvin Alexander
 * [Scala & Design Patterns: Exploring Language Expressivity](http://www.scala-lang.org/old/sites/default/files/FrederikThesis.pdf) - Fredrik Skeel Løkke