+<li><a href="https://download.wpsoftware.net/bitcoin/wizardry/cryptonote-whitepaper.pdf">CryptoNote Whitepaper</a> containing an innovative ring-signature scheme</li>
+</ul>
+
+<a href="http://sagemath.org/">Sage</a> notebooks:
+<ul>
+<li><a href="secp256k1.ecdsa.sage">ECDSA with secp256k1</a>