APA (7th ed.) Citation

Freyd, P. J., & Scedrov, A. (1990). Categories, allegories. North-Holland.

Chicago Style (17th ed.) Citation

Freyd, Peter J., and Andrej Scedrov. Categories, Allegories. Amsterdam: North-Holland, 1990.

MLA (9th ed.) Citation

Freyd, Peter J., and Andrej Scedrov. Categories, Allegories. North-Holland, 1990.