Cita APA (7th ed.)

Freybourg, A. M., & Thomas, A. (2000). Heidi Stern.

Cita Chicago (17th ed.)

Freybourg, Anne Marie, i Annette Thomas. Heidi Stern. Berlin, 2000.

Cita MLA (8th ed.)

Freybourg, Anne Marie, i Annette Thomas. Heidi Stern. 2000.