Heymann, H. (1981). Halbhorn. Kinderbuchverlag.
Cita Chicago (17th ed.)Heymann, Helma. Halbhorn. Berlin: Kinderbuchverlag, 1981.
Cita MLA (8th ed.)Heymann, Helma. Halbhorn. Kinderbuchverlag, 1981.
Atenció: Aquestes cites poden no estar 100% correctes.