Παραπομπή APA

Riodan, R. (2011). Heroes of olympus: The son of neptune. Pengiun books.

Παραπομπή Chicago Style

Riodan, Rick. Heroes of Olympus: The Son of Neptune. London: Pengiun books, 2011.

Παραπομπή MLA

Riodan, Rick. Heroes of Olympus: The Son of Neptune. Pengiun books, 2011.