I bought two books, one from Leedskalnin himself, and one from some author named R L Poole claiming to decode the said leedskalnin texts. I havent actually read either of them yet, got a looooong list of “to reads” in front but they might jump to the front tbh
https://www.amazon.com/Leedskalnin-Codex-Breakthroughs-Understanding-Castle/dp/1794619100