Where to find other summoner tomes?

[welp]

I have played alot of 1.0 so far but i still have yet to find any tomes other then the bat tome. Where do you find the others at?

[Koumori]

There's only two others. One is found in the mold sub-biome, and the other is found in the Sunken Sea.

[zeke]

Same here, so I looked it up on the wiki.

https://core-keeper.fandom.com/wiki/Summon_weapons

It appears there are (disappointingly) only 3.