Guthke, Karl S.2020-07-301986Guthke, Karl S. 1986. The idea of extraterrestrial intelligence. Harvard Library Bulletin XXXIII (2), Spring 1985: 196-210.0017-8136https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37363984en-USJournal Article2020-07-30