Breakneck Battery (English Wikipedia)

"4 Scots busy around Th Rock". 24news.in WorldNews Updated. 15 May 2012. Retrieved 23 October 2012.{{cite news}}: CS1 maint: deprecated archival service (link)

books.google.com (Global: 3^rd place; English: 3^rd place)

"The Late Naval Gunnery Disaster". Illustrated London News. 25 January 1879. Retrieved 3 November 2012.
"Bursting a Great Gun". The New York Times. 4 February 1880. Retrieved 3 November 2012.

"Spur Battery Project Vitello". discovergibraltar.com. DiscoverGibraltar.com (Click Gun Batteries, Spur Battery, then Project Vitello). Archived from the original on 5 September 2013. Retrieved 3 November 2012.
"Spur Battery". discovergibraltar.com. DiscoverGibraltar.com (Click Gun Batteries, Spur Battery). Archived from the original on 5 September 2013. Retrieved 26 October 2012.
"Levant Battery". discovergibraltar.com. DiscoverGibraltar.com (Click Gun Batteries, then Levant Battery). Archived from the original on 5 September 2013. Retrieved 3 November 2012.
"Gun Batteries and Fortifications". discovergibraltar.com. DiscoverGibraltar.com (Click Gun Batteries). Archived from the original on 5 September 2013. Retrieved 28 October 2012.

"Twentieth Century British Coast Defence Guns" (PDF). fsgfort.com. Fortress Study Group. Archived from the original (PDF) on 14 April 2014. Retrieved 3 November 2012.

"Criminal Offences - Restricted Areas Notice" (PDF). gibraltarlaws.gov.gi. Government of Gibraltar. Archived from the original (PDF) on 25 July 2012. Retrieved 25 October 2012.

Roach, John (10 October 2006). "Neandertals' Last Stand was in Gibraltar, Study Suggests". National Geographic News. National Geographic Society. Archived from the original on 14 November 2006. Retrieved 25 October 2012.

"O'Hara's Battery becomes visitor attraction". Gibraltar news from Panorama. 20 May 2012. Retrieved 26 October 2012.
"Scots on the Rock". Gibraltar news from Panorama. 15 May 2012. Retrieved 26 October 2012.

Roach, John (10 October 2006). "Neandertals' Last Stand was in Gibraltar, Study Suggests". National Geographic News. National Geographic Society. Archived from the original on 14 November 2006. Retrieved 25 October 2012.
"Twentieth Century British Coast Defence Guns" (PDF). fsgfort.com. Fortress Study Group. Archived from the original (PDF) on 14 April 2014. Retrieved 3 November 2012.
"Spur Battery Project Vitello". discovergibraltar.com. DiscoverGibraltar.com (Click Gun Batteries, Spur Battery, then Project Vitello). Archived from the original on 5 September 2013. Retrieved 3 November 2012.
"Spur Battery". discovergibraltar.com. DiscoverGibraltar.com (Click Gun Batteries, Spur Battery). Archived from the original on 5 September 2013. Retrieved 26 October 2012.
"Levant Battery". discovergibraltar.com. DiscoverGibraltar.com (Click Gun Batteries, then Levant Battery). Archived from the original on 5 September 2013. Retrieved 3 November 2012.
"Gun Batteries and Fortifications". discovergibraltar.com. DiscoverGibraltar.com (Click Gun Batteries). Archived from the original on 5 September 2013. Retrieved 28 October 2012.
"Criminal Offences - Restricted Areas Notice" (PDF). gibraltarlaws.gov.gi. Government of Gibraltar. Archived from the original (PDF) on 25 July 2012. Retrieved 25 October 2012.