APA (7th ed.) Citation

Pen, J. (1965). Modern economics. Penguin Books.

Chicago Style (17th ed.) Citation

Pen, Jan. Modern Economics. Harmondsworth [etc.]: Penguin Books, 1965.

MLA (9th ed.) Citation

Pen, Jan. Modern Economics. Penguin Books, 1965.

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