There's also the book from Henryk Mach '1/1 game-force' about Precision. An introduction to a simple version of Precision You can download the e-book from: 1/1 Game Force
I tried the system some years ago. There are some seriuos flaws in it, although I can't quite remember which ones. The author told me there is a new version. Especially the 1♣ and 1♦-opening. So I think you should contact him and ask for the improvements. Rory74