APA

Spyri J., Hall E., . (1994). Heidi. London: Puffin books.

Chicago

Spyri Johanna, Hall Eileen, . 1994. Heidi. London: Puffin books.

Harvard

Spyri J., Hall E., . (1994). Heidi. London: Puffin books.

MLA

Spyri Johanna, Hall Eileen, . Heidi. London: Puffin books. 1994.