Conjecture sources

*Preface: It seems we really have a lot of conjectures to formalize.*

We are relatively close to completing the formalization of all the hypotheses from Wikipedia. We are just beginning to formalize the list of Erdős's problems. But I would like to suggest a few more new sources:

- Group theory, [The Kourovka Notebook](https://arxiv.org/pdf/1401.0300)
- Graph theory, [Open Problem Garden](http://www.openproblemgarden.org/category/graph_theory?sort=asc&order=Imp.%C2%B9)
- Ring Theory, [Dniester Notebook](https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=8deec2f4be6e241a4d745708f970ef8f5a591a6a)
- Number Theory,
- [Western Number Theory Problems](https://westcoastnumbertheory.org/problem-sets/)
- *Richard Guy, Unsolved Problems in Number Theory.* But the book is not freely available. I have access to the full text if anyone needs it.

Now more than half of the formalized hypotheses are from number theory. I think this is a good opportunity to dilute number theory with something else.

But most of the questions here are too vague to be formalized.