Some publications have a chemical formula in the title string.
Journals use very different workarounds to export
.bib files for these articles on their website. Some are able to create complicate problems when compiling.
What is the best way to denote a chemical formula in the title field of an article in a .bib file?
Multiferroic phases of Eu1−xYxMnO3 in
PS: I prefer biber, if it makes a difference which tool I use.