How to find number of patents containing NPL in a sector

[Jason_Zhang]

Dear all,

I'm using Global patent index (GPI) and stuck on a "query". How to find number of patents containing NPL (non-patent-literature) in a sector?

Specifically, sector: A61P. Time: 2004/01/01 to present. In this patent group, some patents cited other patents while others cited NPL. So what the query should be to figure out how many of these patents contain NPL?

I tried the query: "PUD>=2004/01/01 and IPC=A61P and not (CNPL=*)" but it doesn't work. I guess "not (CNPL=*)" stands for missing information of NPL in a patent but not "this patent doesn't contain NPL"

Thank you very much! Somebody help me!

Jason

[nico.rasters]

You are probably posting in the wrong forum, unless the Global Patent Index is something that was added to the latest PATSTAT edition?

if you have PATSTAT you can use `tls212_citation`.`npl_publn_id` to get a count of NPL references.
Don't use MAX(`npl_citn_seq_nr`). That only gives the max number for each `citn_origin`.