^« Protests Continue Abroad », في The New York Times, London, Reuters, 22 octobre 1961, ص.
12 ISSN0362-4331
^{{استشهاد ويب
|سلسلة= history.nasa.gov
|عنوان = Beyond the Ionosphere: The Development of Satellite Communications
|مسار = http://history.nasa.gov/SP-4217/intro.htm
|محرر = Andrew J. Butrica
| chapitre = Introduction