Langton, Rae. "Realism or Idealism?." Kantian Humility: Our Ignorance of Things in Themselves. : Oxford University Press, 2001-01-18. Oxford Scholarship Online. 2003-11-01. Date Accessed 18 Jun. 2013 <http://www.oxfordscholarship.com/view/10.1093/0199243174.001.0001/acprof-9780199243174-chapter-11>.
Langton, R.(2001-01-18). Realism or Idealism?. In Kantian Humility: Our Ignorance of Things in Themselves. : Oxford University Press. Retrieved 18 Jun. 2013, from http://www.oxfordscholarship.com/view/10.1093/0199243174.001.0001/acprof-9780199243174-chapter-11.
Langton, Rae. "Realism or Idealism?." In Kantian Humility: Our Ignorance of Things in Themselves. : Oxford University Press, 2001-01-18. http://www.oxfordscholarship.com/view/10.1093/0199243174.001.0001/acprof-9780199243174-chapter-11.
Langton R. Realism or Idealism?. In: Langton R. Kantian Humility: Our Ignorance of Things in Themselves. Oxford University Press; 2001. http://www.oxfordscholarship.com/view/10.1093/0199243174.001.0001/acprof-9780199243174-chapter-11. Accessed June 18, 2013.