Gardner, John. "Can There Be a Written Constitution?." Oxford Studies in Philosophy of Law: Volume 1. : Oxford University Press, 2011-06-01. Oxford Scholarship Online. 2011-09-22. Date Accessed 19 Jun. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199606443.001.0001/acprof-9780199606443-chapter-5>.
Gardner, J.(2011-06-01). Can There Be a Written Constitution?. In Oxford Studies in Philosophy of Law: Volume 1. : Oxford University Press. Retrieved 19 Jun. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199606443.001.0001/acprof-9780199606443-chapter-5.
Gardner, John. "Can There Be a Written Constitution?." In Oxford Studies in Philosophy of Law: Volume 1. : Oxford University Press, 2011-06-01. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199606443.001.0001/acprof-9780199606443-chapter-5.
Gardner J. Can There Be a Written Constitution?. In: Green L, Leiter B. Oxford Studies in Philosophy of Law: Volume 1. Oxford University Press; 2011. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199606443.001.0001/acprof-9780199606443-chapter-5. Accessed June 19, 2013.