Googleがすること・しないこと - Reference http://www.hyperposition.com/se3blog/google/serps/20050609115420.html GoogleGuy Says http://www.markcarey.com/googleguy-says/ GoogleGuy Says - Google Do's and Don'ts http://www.markcarey.com/googleguy-says/archives/discuss-google-dos-and-donts.html