How to refer to someone consistently who has multiple names/spellings?
You cannot make the different spelling variants disappear. So if there is no &quot;official&quot; spelling, all you can do is to pick one of the variants and use it consistently throughout your work. You might choose the most abundant version, or a version used by the person in question, or the most modern version, or the version used in your group...
If this is a critical aspect in your work, you could also include a short discussion of the different spellings of the name and why you picked a specific version. This way, you can also add some context, so the person can be identified more accurately.