Is there a list of what is and isn't OGL in Pathfinder 1E products?

[Mavrickindigo]

Some friends and I are interested in publishing a campaign and 3rd party rules for Pathfinder 1E and we're wondering just what we can and cannot reference in our own stuff. Particularly, we're looking at monsters from the bestiary. For example, can we use the Thriae? Are they OGL or is the fact that they are very different from the mythological Thriae make them Paizo copyright?

If anyone has a list of things we cannot use from books in OGL material, that would be quite helpful.

[gnoams]

Paizo OGL for first edition.