Gaya APA
Riordan, R. (2019).
The Heroes of Olympus 3 : The Mark of Athena (Tanda Athena) .
New York City:
Hachette books group Us.
Gaya MLA
Riordan, Rick.
"The Heroes of Olympus 3 : The Mark of Athena (Tanda Athena)".
New York City:
Hachette books group Us,
2019.
Electronic Resource.