A Lexicon of Thieves Cant

From the introduction:

This lexicon is based on a number of books published between the late 18th and early 20th centuries that examined the historical slang of England, most specifically the area around London. Despite their date of publication, it can be used in FRP campaigns by those who desire a detailed use of thieves cant without the necessity of trying to understand older forms of English which are not particularly intelligible to modern eyes or ears.