(01) http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html
Stars (02) http://www.geocities.com/CapeCanaveral/Launchpad/1364/Stars.html (?)
(03) http://www.enchantedlearning.com/subjects/astronomy/stars/lifecycle/
(04) http://btc.montana.edu/ceres/html/LifeCycle/starsbackground.htm
(05) http://www.windows.ucar.edu/tour/link=/the_universe/Nebula.html
(06) http://www.windows.ucar.edu/tour/link=/the_universe/Strange.html
(07) http://www.windows.ucar.edu/tour/link=/the_universe/Galaxy.html
(08) http://www.ioncmaste.ca/homepage/resources/web_resources/CSA_Astro9/files/html/module2/module2.html#6 (?)
(09) http://outreach.atnf.csiro.au/education/everyone/pulsars/
(10) http://starchild.gsfc.nasa.gov/docs/StarChild/universe_level2/universe.html
(11) http://www.universetoday.com/73222/what-is-a-quasar/
(12) http://www.space.com/scienceastronomy/051212_mystery_monday.html
(13) http://www.space.com/scienceastronomy/merging_backhole_021119.html (?)
(14) http://www.space.com/scienceastronomy/astronomy/spongy_universe_010522-1.html (?)
(15) http://physics.about.com/od/glossary/g/wormhole.htm
(16) http://videos.howstuffworks.com/science-channel/48150-through-the-wormhole-diy-wormhole-video.htm
(17) http://imagine.gsfc.nasa.gov/docs/science/know_l1/neutron_stars.html
(18) http://www.seasky.org/celestial-objects/pulsars.html