Photo, croquis, schéma

http://www.arch.unige.it/e-books/gauthier/pics/tav075.jpg

http://mylifeinhdr.smugmug.com/Other/New-York-CIty/i-rNMhcpM/1/XL/new-york-february-2012-98-2-XL.jpg

http://24.media.tumblr.com/c38746e9fee527f50bdf8b1b449e47aa/tumblr_mpvv71ZTwa1raelhjo1_500.jpg