[abecedarian]

I tried to use Mobipocket Creator (MC) to first convert the pdf to mobi (as suggested on the linked page), and then to convert the mobi to epub in Calibre, but using the IMPORT option for loading the pdf into MC leads to an "import failed" error message. So I guess that's the end to this experiment. But it might be a worthwhile tool for other pdfs if it is willing to import them. But I haven't tried that out yet. For the moment I guess I'm still stuck.

Edit (2020-12-02):
Currently I've resorted to a manual search of the note numbers in the text, somewhat aided by regex in finding and structuring them. I think ABBYY does a much better job in retaining the structure of the text and text formats like superscripts, but on the downside it will also introduce a need for spell checking. I don't know which strategy will be less time consuming: using Calibre or ABBYY.