Any idea where to get a copy of it?, is it worth? As far as I know there are only hardcopies.

Dunno where you could find a copy, perhaps Amazon or ALibris? Personally, I found that by the time I got my copy, I already knew everything it was telling me, but a lot of people seemed to swear by it. YMMV.

I grabbed mine used from an Amazon seller. Search for Harpoon Battlebook and right now it shows 20 sellers have it. I have to say I like the HC (by James DeGoey) better than the "Harpoon II: The Official Strategy Guide (Secrets of the Games) by Ed Dille and Tom Basham".

Thanks for the help, I've found one in the UK in Alibris. I own many of original Harpoon/Harpoon2 paper manuals, but this one was missing in my collection.