I often need to cite working papers and discussion papers (such as those from the National Bureau of Economic Research, http://nber.org/new.html ). It’s normal practice to include the working paper series name and number when citing these.
In Paperpile I have been categorising working papers as “preprint manuscripts”, but the “series” and “series number” fields are not available for this record type. Is it possible to make these two fields available for preprint manuscripts? Or, alternatively, do you recommend categorising working papers in some other way?