1. Drake, F.D. (1983), ‘Estimates of the Relative Probability of Success of the SETI Rearch Program’. SETI Science Working Group Report, NASA Technical Report, Ed. F. Drake, J.H. Wolfe, C.L. Seeger, October 1983, p. 67.
2. Drake, F.D. and Helou, G. (1977), ‘The Optimum Frequencies for Interstellar communications as Influenced by Minimum Bandwidths’, Report 76, National Astronomy and Ionosphere Center, Cornell University, Ithaca, New York.
3. Gulkis, S. (1984), ‘Note on the Optimum Search Strategy for Uniformly Distributed CW Transmitters’, JPL-TDA Progress Report 42-77, p. 144.
4. Oliver, B.M. and Billingham, J. ‘Project Cyclops: A Design Study of a System for Detecting Extraterrestrial Intelligent Life’, prepared under Stanford/NASA/Ames Research Center, 1971 Summer Faculty Fellowship Program Engineering System Design, p. 56.