Simons, Peter. "Supernumeration: Vagueness and Numbers." Cuts and Clouds: Vaguenesss, its Nature, and its Logic. : Oxford University Press, 2010-02-11. Oxford Scholarship Online. 2010-05-01. Date Accessed 22 May. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199570386.001.0001/acprof-9780199570386-chapter-28>.
Simons, P.(2010-02-11). Supernumeration: Vagueness and Numbers. In Cuts and Clouds: Vaguenesss, its Nature, and its Logic. : Oxford University Press. Retrieved 22 May. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199570386.001.0001/acprof-9780199570386-chapter-28.
Simons, Peter. "Supernumeration: Vagueness and Numbers." In Cuts and Clouds: Vaguenesss, its Nature, and its Logic. : Oxford University Press, 2010-02-11. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199570386.001.0001/acprof-9780199570386-chapter-28.
Simons P. Supernumeration: Vagueness and Numbers. In: Dietz R, Moruzzi S. Cuts and Clouds: Vaguenesss, its Nature, and its Logic. Oxford University Press; 2010. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199570386.001.0001/acprof-9780199570386-chapter-28. Accessed May 22, 2013.