APA (7th ed.) Citation

Oppenheim, L. (2008). The League of Nations and its Problems Three Lectures. Project Gutenberg.

Chicago Style (17th ed.) Citation

Oppenheim, L. The League of Nations and Its Problems Three Lectures. Project Gutenberg, 2008.

MLA (9th ed.) Citation

Oppenheim, L. The League of Nations and Its Problems Three Lectures. Project Gutenberg, 2008.

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