<ul>
<li><a href="https://github.com/citp/bitcoin-sok">Bitcoin systematization of knowledge</a>
<li><a href="http://freico.in/docs/freimarkets.pdf">Freimarkets: a bitcoin extension to support user issued assets, p2p lending, options and more.</a>
+<li><a href="https://bitcoin.org/bitcoin.pdf">Bitcoin: A Peer-to-Peer Electronic Cash System</a></li>
</ul>
<a href="http://sagemath.org/">Sage</a> notebooks: