there is a fast and affordable method for removing them." See also Culture jamming Graffiti Sticker art References Further reading "An Asphalt Mystery Examined", April 25, 1999, The New York Times 'Toynbee Tiles' Mystery Resurrected in Philly, September 23, 2006, NPR Weekend Edition "Space Oddity", Kansas City Star, September 6, 2003 Complete text of 4 A.M. by David Mamet "Mystery tiles in St. Louis covered in asphalt", July 4, 2009, the St. Louis Post-Dispatch (via stltoday.com) 2010 Folha.com article Spiegel Online (SPON) article about the Toynbee Tiles (German) External links Toynbee Tile Map Interactive and searchable map of all known Toynbee tiles. Released April 2014. Master site for Toynbee tiles (archived on Wayback Machine), includes list of all known tiles, by city, as of 2003 Archived copy of the site about the Brazilian tiles - deadlink, also connected to http://resurrectdead.proboards.com/ which is also dead 20th-century inscriptions Culture of Philadelphia Graffiti and unauthorised signage Inscriptions of disputed origin Outsider art Space Odyssey Street art