When importing PDFs, Sente always looks first in your library for a match. If Sente is adding new references, it is because your existing references do not match the incoming reference in some important way. For example, if your existing reference does not contain a DOI, Sente will have to look elsewhere for the citation data. Then, it may find the citation information on a site that uses a different abbreviation for the journal name than the reference in your current library, so the duplicate detection code is not sure that the two references are really the same, so it creates a new reference.

It would be good to first check out the original data import problem, so please send us the sample RIS files and we will look to see if our importer is doing something incorrect with them.

Michael