1. www.3gpp.org/
2. en.wikipedia.org/wiki/ dc.internet.com/news/article.php/3083901
3. Prudent engineering practice for cryptographic protocols;Abadi;IEEE Transactions on Software Engineering,1996
4. E. Aboufadel Work by the Poles to break the Enigma codes faculty.gvsu.edu/aboufade/web/enigma/polish.htm
5. en.wikipedia.org/wiki/Access_Control_Matrix