http://www.sen.com/feature/space-law-overview.html Sen - Space exploration network en PressRelease, Opinion 2012-02-22 International space law - an overview Space law, Outer Space Treaty 1967 http://www.sen.com/dailynews/22022012.html Sen - Space exploration network en PressRelease, Opinion 2012-02-22 Scientists discover waterworld http://www.sen.com/dailynews/21022012.html Sen - Space exploration network en PressRelease, Opinion 2012-02-21 End in sight for Herschel Space Telescope