APA (7th ed.) Citation

Perkins, L. F. (2009). The Mexican Twins. Project Gutenberg.

Chicago Style (17th ed.) Citation

Perkins, Lucy Fitch. The Mexican Twins. Project Gutenberg, 2009.

MLA (9th ed.) Citation

Perkins, Lucy Fitch. The Mexican Twins. Project Gutenberg, 2009.

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