Reflector sight (English Wikipedia)

Lockyer, Sir Norman (1902). Nature. Macmillan Journals Limited. p. 227. Retrieved 13 April 2018 – via Internet Archive. grubb for sighting devices for guns.

books.google.com

"Elementary Optics and Application to Fire Control Instruments". Headquarters, Department of the Army. 13 April 1977. Retrieved 13 April 2018 – via Google Books.
Company, McGraw-Hill Book (13 April 2018). McGraw-Hill encyclopedia of science and technology. McGraw-Hill. ISBN 9780079136657. Retrieved 13 April 2018 – via Google Books. {{cite book}}: |last= has generic name (help)
Ray, Sidney F. (13 April 2018). Applied Photographic Optics: Lenses and Optical Systems for Photography, Film, Video, Electronic and Digital Imaging. Focal. ISBN 9780240515403. Retrieved 13 April 2018 – via Google Books.
"Science Progress". John Murray. 13 April 1992. Retrieved 13 April 2018 – via Google Books.
"The Scientific Transactions of the Royal Dublin Society". The Society. 13 April 2018. Retrieved 13 April 2018 – via Google Books.
"The Mining engineer, Volume 23 By Institution of Mining Engineers (Great Britain). THE GRUBB SIGHT FOR SURVEYING INSTRUMENTS By Sir HOWARD GRUBB and HENRY DAVIS". google.com. 1903. Retrieved 13 April 2018.
Harry Woodman (1989). Early aircraft armament: the aeroplane and the gun up to 1918. p. 239. ISBN 9780874749946.
Ohio, United States Document Service Center, Dayton (13 April 2018). "Technical Data Digest". Retrieved 13 April 2018 – via Google Books.{{cite web}}: CS1 maint: multiple names: authors list (link)
Shideler, Dan (14 July 2010). Gun Digest 2011. Krause Publications. ISBN 9781440215612. Retrieved 13 April 2018 – via Google Books.
Jones, Tony L. (1 January 2002). The Police Officer's Guide to Operating and Surviving in Low-light and No-light Conditions: How to Prevail in Stressful Situations Through Proper Decision Making and Instruction on the Use and Availability of Illumination Tools. Charles C Thomas Publisher. ISBN 9780398072537. Retrieved 13 April 2018 – via Google Books.
Jarrett, D. N. (13 April 2018). Cockpit Engineering. Ashgate Pub. ISBN 9780754617518. Retrieved 13 April 2018 – via Google Books.
McIntyre, Thomas (1 December 2007). The Field and Stream Hunting Optics Handbook: An Expert's Guide to Riflescopes, Binoculars, Spotting Scopes, and Rangefinders. Lyons Press. ISBN 9781599210445. Retrieved 13 April 2018 – via Google Books.
Mullaney, James (26 May 2007). A Buyer's and User's Guide to Astronomical Telescopes & Binoculars. Springer Science & Business Media. ISBN 9781846287077. Retrieved 13 April 2018 – via Google Books.
Dept, United States Army Ordnance (13 April 2018). "Elementary Optics and Applications to Fire Control Instruments: May, 1921". U.S. Government Printing Office. Retrieved 13 April 2018 – via Google Books.
Magazines, Hearst (1 September 1970). "Popular Mechanics". Hearst Magazines. Retrieved 13 April 2018 – via Google Books.

bullseyepistol.com

"Encyclopedia of Bullseye Pistol". www.bullseyepistol.com. Retrieved 13 April 2018.

company7.com

"Telrad Sight". Company Seven. Retrieved 17 January 2016.

google.com

""Compact Holographic Sight" - EOTech company Patent #5,483,362 issued January 9, 1996" (PDF). google.com. Retrieved 13 April 2018.^{[dead link‍]}

hineslab.com

"The Hines Lensless Optical Viewfinder". hineslab.com. Archived from the original on 23 March 2012. Retrieved 13 April 2018.

liberatorcrew.com

"Aircraft Gunnery_Sights". liberatorcrew.com. Retrieved 13 April 2018.

patents.google.com

U.S. patent 2633051A

usmilitariaforum.com

"BAZOOKA M9A1". usmilitariaforum.com. Archived from the original on 6 August 2017. Retrieved 13 April 2018.

web.archive.org

"BAZOOKA M9A1". usmilitariaforum.com. Archived from the original on 6 August 2017. Retrieved 13 April 2018.
"The Hines Lensless Optical Viewfinder". hineslab.com. Archived from the original on 23 March 2012. Retrieved 13 April 2018.