It isn’t easy, but it is possible. See www.adeptscience.co.uk/kb/article/A5BA is as good a place as any to start. Don’t forget to read it all the way to the end, as it quotes some other resource pages.
but if you are in a field that has a public database (pubmed for science or library of congress for books of any kind) or if you have access to a relevant database thru your institution, it is really much easier to go and collect the references than massaging the text file.