Delbert R. Terrill, Jr.

http://www.sworld.com.au/steven/space/

http://www.astronautix.com

http://www.nasaspaceflight.com

http://www.russianspaceweb.com/

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http://adsabs.harvard.edu/abs/1962QJRAS...3...99.

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http://orbitaldebris.jsc.nasa.gov/newsletter/pdfs/ODQNv17i4.pdf

http://www.spacearchive.info/index.htm

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http://www.au.af.mil/au/awc/awcgate/space/terrill.pdf

http://doi.org/10.1109%2Fproc.1964.2992

http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?tp=&arnumber=1444922&isnumber=31060