I have a digital library and I need a simple database tool to search among my .pdf printouts.
My problem is this: I have books, book chapters, dissertations and research papers. So, those are four categories. Moreover, I have four different topics that I conduct research on. That is another four categories.
If I try to use the file system, there will clearly be duplicates.
What I want is to be able to filter/search the materials I have with respect to their type and area, without dealing with duplicates.
I use Windows 10, but occasionally, I may use it on Ubuntu. Thus, cross-platform would be a great thing to have, but mainly I'm looking for Windows.