APA (7th ed.) Citation

Shelley, M. (1994). Frankenstein: Or, The modern Prometheus. Penguin Books.

Chicago Style (17th ed.) Citation

Shelley, Mary. Frankenstein: Or, The Modern Prometheus. London: Penguin Books, 1994.

MLA (9th ed.) Citation

Shelley, Mary. Frankenstein: Or, The Modern Prometheus. Penguin Books, 1994.