(first mention)
Elizabeth Lister, Scratches in the Sky: The Battle of Britain (2005),<http://www.bbc.co.uk/history/ww2peopleswar/stories/90/a4354490.shtml> [accessed 13 September 2023] (para. 3 of 7).
(subsequent mentions)
Lister, para. 4 of 7.
Lister, Elizabeth, Scratches in the Sky: The Battle of Britain (2005), <http://www.bbc.co.uk/history/ww2peopleswar/stories/90/a
4354490.shtml> [accessed 13 September 2023] (para. 3 of 7)