fb pixel FOTO #3: Galileo Galilei – G.cz
Galileovy zápisky By Galileo Galilei - http://www2.jpl.nasa.gov/galileo/ganymede/discovery.html (direct link). Above English description and translation: http://www.lib.umich.edu/special-collections-library/galileo-manuscript, Public Domain, https://commons.wikimedia.org/w