[1] [CITE[rel=canonical — Anne’s Weblog]] ([TIME[2009-02-17 10:26:13 +09:00]] 版) <http://annevankesteren.nl/2009/02/rel-canonical>

[2] [CITE[Official Google Webmaster Central Blog: Specify your canonical]] ([TIME[2009-02-28 13:56:40 +09:00]] 版) <http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html>