Refer: http://www.noupe.com/development/collection-of-the-coolest-uses-of-the-google-maps-api.html https://developers.google.com/maps/documentation/javascript/examples/circle-simple https://www.youtube.com/watch?v=j9ZO4mTDAtM https://www.youtube.com/watch?v=lVhDux1vmIU&index=2&list=PLLXj22DZPPaBxqgxFHAIP-k1-ZIIVAa-K http://www.ajaxtower.jp/googlemaps/ http://www.tam-tam.co.jp/tipsnote/javascript/post7755.html http://lopan.jp/google-maps-api/ http://www.openspc2.org/reibun/Google/Maps/API/ver3/ http://www.docin.com/p-511799015.html http://www.docin.com/p-268566931.html http://www.docin.com/p-6970434.html