APA (7th ed.) Citation

Ingersoll, R. G. (1951). The letters. Philosophical Library.

Chicago Style (17th ed.) Citation

Ingersoll, Robert Green. The Letters. New York: Philosophical Library, 1951.

MLA (9th ed.) Citation

Ingersoll, Robert Green. The Letters. Philosophical Library, 1951.

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