Diagram showing the German Ruhrstahl X-4 air-to-air missile, developed during the Second World War.
USN
<a rel="nofollow" class="external text" href="http://www.navy.mil/ah_online/department_arch.html">U.S. Navy All Hands magazine</a> <a rel="nofollow" class="external text" href="http://www.navy.mil/ah_online/archpdf/ah195703.pdf">March 1957</a>, p. 22.