http://www.youtube.com/watch?feature=player_embedded&v=WZ5QzF88SHw
http://www.home-biology.gr/index.php/ilektromagnitikes-aktinovolies-egimosini-paidia-aftismos
http://www.home-biology.gr/index.php/ilektromagnitikes-aktinovolies-egimosini-paidia-aftismos
http://www.home-biology.gr/