Those are monsters from TSR Fiend Folio and Monster Manual 2, for AD&D 1e, converted for Swords and Wizardry Complete Revised. I did some rules adaptations or lore interpretations in some places, but do not claim any right to this content. This is done only as free fan content.
I had to use it a lot last March for my campaign and noticed some typos are still there, so I might do a revision of the document. I could then check for some usability upgrades as you suggest.
My name and all legal mumbo jumbo are all on the project page and that's the only place it's available, but still, it's true I could include parts or all of it in the document too.
Thanks a lot for your comment, glad you appreciated it :).