1. Bertola, F. (1992) Da Galileo alle Stelle. Biblos Edizioni, Padua. [This book was published during the celebrations at the University of Padua to commemorate the fourth century of the nomination of Galileo Galilei as a lecturer of Mathematics in that university, where he spent 18 years of very productive work.]
2. Europa Ocean Conference at San Juan Capistrano Research Institute. 12-14 November, 1996. Book of summaries (pp. 90). San Juan Capistrano Research Institute. 31872 Camino Capistrano. San Juan Capistrano, CA 92675.
3. Feinberg, G. and Shapiro, R. (1980) Life beyond Earth: The intelligent Earthling’s Guide to Life in the Universe, William Morrow and Co., New York, pp. 328-332.
4. Greenberg, R. (2005) Europa: The Ocean Moon: Search for an Alien Biosphere, Springer Praxis Books.
5. Greenberg, R. (2008) Unmasking Europa: the search for life on Jupiter’s ocean moon. Copernicus Books, 277 pp.