1. CHAM, Jorge. Addicted to the web. Pilled Higher & Deeper: a grad student comic strip [online]. 2010-05-08 [cit. 2011-01-06]. Obrázek ve formátu GIF. Dostupné z: http://www.phdcomics.com/comics/archive.php?comicid=185.
  2. SIMIEZZZ. Iconscollection – Mail [online]. 2007-09-02. Attribution-NoDerivs 2.0 Generic (CC BY-ND 2.0) [cit. 2011-01-27]. Obrázek ve formátu JPEG. Dostupné z: http://www.flickr.com/photos/simiezzz/1301796545/.
  3. SIMIEZZZ. Iconscollection – Mail [online]. 2007-08-11. Attribution-NoDerivs 2.0 Generic (CC BY-ND 2.0) [cit. 2011-01-27]. Obrázek ve formátu JPEG. Dostupné z:http://www.flickr.com/photos/simiezzz/1081911996/.
  4. SIMIEZZZ. Iconscollection – Wait a minute [online]. 2007-08-11. Attribution-NoDerivs 2.0 Generic (CC BY-ND 2.0) [cit. 2011-01-27]. Obrázek ve formátu JPEG. Dostupné z:http://www.flickr.com/photos/simiezzz/1081057895/.