APA (7th ed.) Citation

Simmons, H. (2011). An introduction to category theory (0rig. publ.). Cambridge Univ. Press.

Chicago Style (17th ed.) Citation

Simmons, Harold. An Introduction to Category Theory. 0rig. publ. Cambridge [u.a.]: Cambridge Univ. Press, 2011.

MLA (9th ed.) Citation

Simmons, Harold. An Introduction to Category Theory. 0rig. publ. Cambridge Univ. Press, 2011.

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