Golay's [single page paper][1] describing what is today known as Golay code, a perfect code of length 23. This is even used in NASA deep space missions, and is one of the only perfect codes which are not Hamming codes.


  [1]: https://web.archive.org/web/20150419200849/http://www.maths.manchester.ac.uk/~ybazlov/code/golay_paper.pdf