Ancient Greek not supported

Hey guys, so my kindle does not support Greek fonts so I needed to find a way to read ebooks written in Greek that I purchase from Greek online bookstores. After some research, I just downloaded ADE on my phone and I read them from there. I bought this book about Delphi and it has a lot of words in Ancient Greek which looks like it's not supported because they show like hieroglyphics lol. Anyway I can fix this?