It seems that BibTeX materials can be written as XML.
Here are some resources I found on this:
- a python2 script: https://www.eecis.udel.edu/~sprenkle/bibtex2html/bibtex2xml.py
- an overview presentation: https://pdfs.semanticscholar.org/8c8e/44b18bacac15f14113af3d4b55f028e0a842.pdf
- Software Package: http://www.sfs.uni-tuebingen.de/hpsg/archive/projects/bibtex2html/
- Prior research: https://web.science.mq.edu.au/~rdale/resources/bibtex/index.html
- maybe some XSLT files: https://sourceforge.net/projects/bibtexml/