Leni,
As with all other "art forms", buying paperweight books depends on your own current focus. There are books on all sorts of "collectable" weights from all sorts of countries.
I suggest starting at the Sweetbriar Gallery booklist
http://www.sweetbriar.co.uk/booklist.phpThey have a good supply, both second-hand and new.
However, other than Pat Reilly's
Paperweights, which is an excellent guide (and I'm not just saying that because I know Pat from the Paperweight Club) you already have two of the best books for basics - Jargstorf's and Flemming / Pommerencke's.
Which way do you see your interest developing? Whichever way that goes, there are books to cover it - unless you choose to follow modern English studio work, for which I am not aware of any titles.
Finally, as a new PCC member (when you get your card) have you checked out the PCC diary on the website? Our guest speaker for 11th June is none other than Sibylle Jargstorf.