“The New Pressurised Marksman”. Air-Britain Heston. Heston and Heathrow Branch of Air-Britain (24 April 2010). 23 Jul 2012時点のオリジナルよりアーカイブ。27 January 2020閲覧。。
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abheston.btinternet.co.uk
“The New Pressurised Marksman”. Air-Britain Heston. Heston and Heathrow Branch of Air-Britain (24 April 2010). 23 Jul 2012時点のオリジナルよりアーカイブ。27 January 2020閲覧。。