APA (7th ed.) Citation

Spyri, J. (2007). Heidi. Project Gutenberg.

Chicago Style (17th ed.) Citation

Spyri, Johanna. Heidi. Project Gutenberg, 2007.

MLA (9th ed.) Citation

Spyri, Johanna. Heidi. Project Gutenberg, 2007.

Warning: These citations may not always be 100% accurate.