APA (7th ed.) Citation

Priestley, J. (2009). Experiments and Observations on Different Kinds of Air. Project Gutenberg.

Chicago Style (17th ed.) Citation

Priestley, Joseph. Experiments and Observations on Different Kinds of Air. Project Gutenberg, 2009.

MLA (9th ed.) Citation

Priestley, Joseph. Experiments and Observations on Different Kinds of Air. Project Gutenberg, 2009.

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