APA

Clark، Julie, . (2008). The 10 most essential chemical messengers in the body. New York: scholastic.

Chicago

Clark، Julie, . 2008. The 10 most essential chemical messengers in the body. New York: scholastic.

Harvard

Clark، Julie, . (2008). The 10 most essential chemical messengers in the body. New York: scholastic.

MLA

Clark، Julie, . The 10 most essential chemical messengers in the body. New York: scholastic. 2008.