APA (7th ed.) Citation

Hadamard, J. (2009). Four Lectures on Mathematics, Delivered at Columbia University in 1911. Project Gutenberg.

Chicago Style (17th ed.) Citation

Hadamard, Jacques. Four Lectures on Mathematics, Delivered at Columbia University in 1911. Project Gutenberg, 2009.

MLA (9th ed.) Citation

Hadamard, Jacques. Four Lectures on Mathematics, Delivered at Columbia University in 1911. Project Gutenberg, 2009.

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