APA (7th ed.) Citation

Spinoza, B. d. (1999). The ethics, Part I. Project Gutenberg.

Chicago Style (17th ed.) Citation

Spinoza, Benedictus de. The Ethics, Part I. Champaign, Ill: Project Gutenberg, 1999.

MLA (9th ed.) Citation

Spinoza, Benedictus de. The Ethics, Part I. Project Gutenberg, 1999.

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