แหล่งที่มา WikiPedia: เขตขั้วโลก http://www.barrameda.com.ar/ecology/the-polar-regi... http://www.mnh.si.edu/arctic/index.html http://www.windows.ucar.edu/polar.html http://polardiscovery.whoi.edu/ http://maps.grida.no/arctic/ http://www.panda.org/news_facts/education/middle_s... http://www.polarfoundation.org/ http://www.spri.cam.ac.uk/ http://www.guardian.co.uk/environment/gallery/2007... https://curlie.org/Regional/Polar_Regions/
