archive.org/web/20161014042614/http://www.panoramio.com/user/1753611?with_photo_id=27453529 operator: Panoramio described at URL: https://web.archive...
pdf English: RODRÍGUEZ POSADA, Emilio José; GONZÁLEZ BERDASCO, Ángel; SIERRA CANDUELA, Jorge A.; NAVARRO SANZ, Santiago; SAORÍN, Tomás (2012). "Wiki...
w/n14-rodriguez-gonzalez-sierra-navarro-saorin Author Emilio José Rodríguez Posada, Ángel González Berdasco, Jorge A. Sierra Canduela, Santiago Navarro...
English operator: Panoramio described at URL: https://web.archive.org/web/20161102142049/http://www.panoramio.com/photo/123966369 determination method...
panoramio.com/user/12384?with_photo_id=758308 operator: Panoramio described at URL: https://web.archive.org/web/20161010131848/http://www.panoramio.com/photo/758308...