I use biblatex-chicago for writing my PhD thesis, and I have only one file for the bibliography. I need to separate my bibliography into primary and secondary sources. From what I understand about the existing solutions on the forum and the documentation, it is only possible to either sort manually each entry with a ‹type› (or keyword), or to make two bib files (one source and one secondary literature).
I was wondering if there was a way to print the bibliography sorting primary sources and secondary sources without going manually in every citation in my bib file as ‹type› or ‹keyword› "source" or "secondary literature". I may be wrong but it doesn't seem that the year of publication is accepted as a key and a value. Isn't there a way to print only entries that are within a specified range of dates?