SOURCES
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Clerke, Agnes Mary (2011) A Popular History of Astronomy During the Nineteenth Century. Cambridge University Press, UK.
Greg, Percy (1880) Across the Zodiac: The Story of a Wrecked Record. Ballantyne Press, London, UK.
Crossley, Robert (2011) Imagining Mars: A Literary History. Wesleyan University Press, CT, USA.
Tipler, F.J. (1981) A Brief History of the Extraterrestrial Intelligence Concept. Quarterly Journal of the Royal Astronomical Society, Vol. 22, P. 133, 1981.