1. 〈http://www.nikonusa.com/〉 as of 30 August 2008.
2. 〈http://www.microtekusa.com/〉 as of 30 August 2008.
3. 〈http://www.usa.canon.com/〉 as of 30 August 2008.
4. 〈http://www.red.com/〉 as of 30 August 2008.
5. 〈http://www.veterinaryvision.com/See.htm〉 as of 30 August 2008.