APA (7th ed.) Citation

Waldeyer, G. (2007). The 4-D Doodler. Project Gutenberg.

Chicago Style (17th ed.) Citation

Waldeyer, Graph. The 4-D Doodler. Project Gutenberg, 2007.

MLA (9th ed.) Citation

Waldeyer, Graph. The 4-D Doodler. Project Gutenberg, 2007.

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