*. [http://iopscience.iop.org/article/10.1088/0305-4608/5/5/017/meta;jsessionid=4B8D9A38523A828CD28C8CE67DD973E8.c5.iopscience.cld.iop.org ShieldSquare Captcha]
*. [https://archive.today/20130415143828/http://papercore.org/Sherrington1975 Papercore Summary http://papercore.org/Sherrington1975]
* [https://archive.today/20130415190815/http://papercore.org/Parisi1980 Papercore Summary http://papercore.org/Parisi1980].