レーダーの歴史
Christian Hülsmeyer and about the early days of radar inventions (PDF, 1.64 MiB)
Hollmann, Martin, "Radar Family Tree". Radar World.
The first operational radar in France 1934 - via archive.org
Penley, Bill, and Jonathan Penley, "Early Radar History - an Introduction". 2002.
Buderi, "Telephone History: Radar History". Privateline.com. (Anecdotal account of the carriage of the world's first high power cavity magnetron from Britain to the US during WW2.