(I do not own these, I helped in the creation of the FORC website though)
HORG: The first occlupanid website, the bible of collectors, the place with every single known species!
FORC: A discord group for occlupanologists.
R/Occlupanids: The Reddit group for occlupanologists.
Occlupanid Hand Guide(USA): Made by me, all of the most common to see occlupanids in US stores.
Unknown species list: Made by a occlupanologist in the FORC, this list shows most occlupanids that do not have an entry in HORG.