In addition there is a wealth of letters to and from Bessler or about him which I have included in my book about the life of Johann Bessler, see below how to obtain a copy of my book.
In addition there is a copy of his unpublished document containing some 141 drawings, entitled Maschinen Tractate. This document was intended to form a teaching aid to be used by Bessler in a school for apprentices which he wished to found with the money he hoped to obtain for his invention.
My own account of Bessler’s life is also available from the links. It is called "Perpetual Motion; An Ancient Mystery Solved?"
Johann Bessler three published books are entitled; "Grundlicher Bericht", "Apologia Poetica" and "Das Triumphirende..."
I have also published Bessler's collection of 141 drawings and I have called it Maschinen Tractate, but it was originally found in the form of a number of drawings of perpetual motion designs. Many of these have handwritten notes attached and I have published the best English translation of them that I was able to get. Bessler never published these drawings but clearly intended to do so at some point.
For some ideas about Bessler’s code why not visit one of my web sites at www.theorffyreuscode.com
A separate web site deals with another piece of code found in his book Apologia Poetica, at www.orffyreus.net