http://www.skyscript.co.uk/ezra.html
http://cura.free.fr/cura2/901meira.html
https://www.jewishvirtuallibrary.org/jsource/judaica/ejud_0002_0002_0_01531.html
http://www.come-and-hear.com/shabbath/shabbath_156.html
http://www.jewishencyclopedia.com/articles/2051-astrology
http://www.pitt.edu/~brg/pdfs/brg_ii_2.pdf
https://en.wikipedia.org/wiki/Jewish_views_on_astrology
https://en.wikipedia.org/wiki/Gersonides
http://shiratdevorah.blogspot.com/p/jewish-astrology.html
