APA

Riordan R., . (2009). Percy Jackson. London: Puffin Books.

Chicago

Riordan Rick, . 2009. Percy Jackson. London: Puffin Books.

Harvard

Riordan R., . (2009). Percy Jackson. London: Puffin Books.

MLA

Riordan Rick, . Percy Jackson. London: Puffin Books. 2009.