Series
Las pruebas de Apolo
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.
4 books here
Publication order
This is publication order — nobody has confirmed a different reading order for this one yet.
1
The Hidden Oracle
· Rick Riordan
2
The Dark Prophecy
· Rick Riordan
4
The Tyrant's Tomb
· Rick Riordan
—
The Burning Maze
· Rick Riordan