... American Astronomical Society . AstroWeb: Astronomy/Astrophysics on the Internet . ... NASA Astrophysics Data System: Abstract Service . ... Astronomy Astrophysics: Preprints Abstracts . ... Local archive of IAU Circulars. ... Germany, list of all Astronomical Institutes . ... Poland, Warsaw University Astronomical Observatory . Russia, Sternberg Astronomical Institute . ... Russia, Institute of Astronomy, Russian Academy of Sciences . ... USA, Astronomy and Space Science Group at GMU . ...