APA (7th ed.) Citation

(1990). The golden mean [golden ratio]. Project Gutenberg.

Chicago Style (17th ed.) Citation

The Golden Mean [golden Ratio]. Champaign, Ill: Project Gutenberg, 1990.

MLA (9th ed.) Citation

The Golden Mean [golden Ratio]. Project Gutenberg, 1990.

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