Sources for Pages of Theosophistical Notes?

Going at Bullbone Island gives mostly Cryptopaleontological Notes.
Going at Corpsecage Island provides us with Prelapsarian Archaeological Notes.

What’s the main source for Teosophistical Notes? Is there anything I overlooked?

Grunting Fen is the third island! That one lives in the Sea of Voices, which you need a Screaming Map to get to, I think. It’s slightly more out of the way than the other two.

Ok, thanks. I can get to the Sea of Voices. Until now, in that region I have only been briefly to Polythreme.