APA (7e ed.) Bronvermelding

Willis, J., & Ross, T. (2012). Hippospotamus (American ed.). Andersen Press USA : Distributed in the United States by Lerner.

Chicago (17e ed.) Bronvermelding

Willis, Jeanne, en Tony Ross. Hippospotamus. American ed. Minneapolis: Andersen Press USA : Distributed in the United States by Lerner, 2012.

MLA (8e ed.) Bronvermelding

Willis, Jeanne, en Tony Ross. Hippospotamus. American ed. Andersen Press USA : Distributed in the United States by Lerner, 2012.