does anyone know a few good books on hj knives, thanks

I don't think there are any books that deal exclusively with HJ knives. However, almost all of the excellent books on German WWII daggers, will have lots of information about HJ knife.

Ron Weinand NPEA Daggers and Associated Knives has info on HJ blades and variations see Ebay 270383495670 for a copy currently on offer
Ron may still have copies

Thanks AJ. Also, I have some new ones in the latest book: Waffenleite presenting NPEA Daggers of the Third Reich. Both books are discounted to GermanDaggers.com members.
Ron Weinand

Had forgotten about the ones in the new book Ron time to read that one again I guess tend to read when first obtained and then leave on the shelf.