http://books.google.de/books/about/Ars_ ... edir_esc=y
has nothing, but gives the title, and it seems to have been produced in Cologne
gives info about a production in Leipzig. Petrarca is given as the author, but ...
Petrarca is not the author, but Coluccio Salutati.Note: "Anm. Autor der „Ars punctandi“ ist nicht Petrarca, sondern Coluccio Salutati, vgl. Hirsch, Rudolf: Printing, selling and reading 1450–1550. Wiesbaden 1974."
Anyway, it's interesting, that Salutati was interested in geomancy.