I am a masters student in the process of writing a thesis in computer science.
In particular, there is someone who works in industry who is probably one of, if not the world leading experts in a particular kind of mathematical set of functions. However this person is very much not an academic, he is an industry researcher whose primary objective is practical applications rather than publishing papers.
He maintains a personal blog where he explains a lot of concepts related to this topic in depth. I have used and referenced his blog religiously all through my masters. For example he has a list of functions in this class that can be used to construct very interesting things as well as which operations can be used to combine them.
I know some of these functions he didn't make, they have been known if not since antiquity, at least since the middle ages, others he may have come up with or may have heard about them from someone else and just wrote them in his blog.
What do I do here? It seems like I should cite him since this resource is probably the thing I referenced the most through my masters, but he is probably not the first author of most of the concepts in there, but for many, the first author is likely lost to history.