http://ssd.jpl.nasa.gov/horizons.cgi
http://space.jpl.nasa.gov/
http://www.fourmilab.ch/
http://aa.usno.navy.mil/
http://aiuas3.unibe.ch/dpgm/zm_graph_tide.html
skytonight
http://www.rudolfhsmit.nl/hpage.htm
http://www.ifj.edu.pl/~stachnie/astrole.html
http://cura.free.fr/docum/15kep-en.html
http://www.cheorae.it/
http://www.planetos.info/
almagest
http://www.youtube.com/watch?v=3Dp2Zqk8vHw
http://www.youtube.com/watch?v=a24zZ8DdMK4&mode=related&search=
http://www.youtube.com/watch?v=pmWSOP2uPj4
http://www.youtube.com/watch?v=oQPFoDkGFrU
http://www.youtube.com/watch?v=6TkWHcHl03Q
http://www.youtube.com/watch?v=2450wrLocKs&mode=related&search=
http://www.youtube.com/watch?v=DnCgT5uDHiI
http://www.youtube.com/watch?v=5rDRpyLkces
http://www.youtube.com/watch?v=ubnLBSoZ1Io
http://www.youtube.com/watch?v=zYTxVUgaUPg
http://www.youtube.com/watch?v=xwQTS6yuQhU
http://www.youtube.com/watch?v=coBPABdDpUs