"Gí-bó pîn-lu̍t" pán-pún chi-kan bô-kāng--ê tē-hng

*[[Jī-bó-hē]]

 

* [https://web.archive.org/web/20070402181401/http://pages.central.edu/emp/LintonT/ A site with content of ''Cryptographical Mathematics''] by Robert Edward Lewand

* [http://www.bckelk.ukfsn.org/words/etaoin.html Some examples of letter frequency rankings in some common languages]