Drive time isochrones around airports in northern Finland
Anita Graser
CC BY 3.0
<a rel="nofollow" class="external text" href="http://underdark.wordpress.com/2011/02/12/drive-time-isochrones/">Free and Open Source GIS Ramblings</a> using spatial data (roads and locations) <a rel="nofollow" class="external text" href="http://www.maanmittauslaitos.fi/en/node/6567">© National Land Survey of Finland 2011</a>