APA Style

Riordan, R. (2011). The son of Neptune : # 2 of Heroes of Olympus #2 (1st ed). New York: Disney/Hyperion Books.

MLA Style

Riordan, Rick. "The son of Neptune : # 2 of Heroes of Olympus #2". 1st ed New York: Disney/Hyperion Books, 2011. Text.