De Valois, Russell L., and Karen K. De Valois. "Linear Systems Analysis." Spatial Vision. : Oxford University Press, 1991-06-20. Oxford Scholarship Online. 2008-01-01. Date Accessed 20 Jun. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195066579.001.0001/acprof-9780195066579-chapter-1>.
De Valois, R., & De Valois, K.(1991-06-20). Linear Systems Analysis. In Spatial Vision. : Oxford University Press. Retrieved 20 Jun. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195066579.001.0001/acprof-9780195066579-chapter-1.
De Valois, Russell L., and Karen K. De Valois. "Linear Systems Analysis." In Spatial Vision. : Oxford University Press, 1991-06-20. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195066579.001.0001/acprof-9780195066579-chapter-1.
De Valois RL, De Valois KK. Linear Systems Analysis. In: DeValois RL, DeValois KK. Spatial Vision. Oxford University Press; 1991. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195066579.001.0001/acprof-9780195066579-chapter-1. Accessed June 20, 2013.