Videá:
https://www.youtube.com/watch?v=ulLU1BUJk8Q
https://www.youtube.com/watch?v=tcuf_tglwEg
https://www.youtube.com/watch?v=_opAMkK95gE
https://www.youtube.com/watch?v=BiMGriomhtw
Webstránky:
http://www.thisiscolossal.com/2012/04/gravity-defying-land-art-by-cornel...
http://sacredecologyfilms.com/environmental-artist-nils-udo/
http://chrisdrury.co.uk/
http://www.richardshilling.co.uk/