1. Rejuvenating the Sun and Avoiding Other Global Catastrophes;Beech,2008
2. G. Lemarchand, Detectability of Extraterrestrial Technological Activities. 〈http://www.coseti.org/lemarch1.htm〉. (Date accessed 26 October 2009).
3. How can we detect radio transmissions from distant planetary systems?;Drake;Sky Telesc.,1960
4. Transmission of information by extraterrestrial civilizations;Kardashev;Sov. Astro,1964
5. Search for artificial stellar sources of infrared radiation;Dyson;Science,1960