Series
Geroi Olimpa -- kniga
We don't know whether this one is finished.
Nobody has confirmed the status of this series yet. That's a gap in our data, not a verdict on the books.
3 books here
Publication order
This is publication order — nobody has confirmed a different reading order for this one yet.
1
The Lost Hero
· Rick Riordan
4
The House of Hades
· Rick Riordan
5
The Blood of Olympus
· Rick Riordan