Hail doesn’t have a prepackaged ‘gwas’ method, so the documentation is on each specific method that might be used to do per-variant association tests, which you can find on the statistical methods page:
Note that these methods are not called “gwas” because they are useful outside of variant association – these same methods work after aggregating rare variants per gene in a burden test, for instance!
You can absolutely cite the software, there’s a
hl.citation method that generates versioned links for reproducibility:
Hail Team. Hail 0.2.13-81ab564db2b4. https://github.com/hail-is/hail/releases/tag/0.2.13.