APA (7th ed.) Citation

Columbus, C., Casas, B. d. l., Vespucci, A., & Markham, C. R. (2011). The Letters of Amerigo Vespucci and other documents illustrative of his career. Project Gutenberg.

Chicago Style (17th ed.) Citation

Columbus, Christopher, Bartolomé de las Casas, Amerigo Vespucci, and Clements R. Markham. The Letters of Amerigo Vespucci and Other Documents Illustrative of His Career. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Columbus, Christopher, et al. The Letters of Amerigo Vespucci and Other Documents Illustrative of His Career. Project Gutenberg, 2011.

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