Added Ethical Artificial Intelligence

Added Ethical Artificial Intelligence to the Free Content section. This book combines several peer reviewed papers and new material to analyze the issues of ethical AI.

README.md

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 * [Artificial Intelligence and Molecular Biology](http://www.biosino.org/mirror/www.aaai.org/Press/Books/Hunter/hunter-contents.html) - The current volume is an effort to bridge that range of exploration, from nucleotide to abstract concept, in contemporary AI/MB research.
 * [Brief Introduction to Educational Implications of Artificial Intelligence](http://pages.uoregon.edu/moursund/Books/AIBook/index.htm) - This book is designed to help preservice and inservice teachers learn about some of the educational implications of current uses of Artificial Intelligence as an aid to solving problems and accomplishing tasks. 
 * [Encyclopedia:Computational intelligence](http://www.scholarpedia.org/article/Encyclopedia_of_computational_intelligence) - Scholarpedia is a peer-reviewed open-access encyclopedia written and maintained by scholarly experts from around the world.
+* [Ethical Artificial Intelligence](http://arxiv.org/abs/1411.1373) - a book by Bill Hibbard that combines several peer reviewed papers and new material to analyze the issues of ethical artificial intelligence.
 
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