http://www.larazon.es/detalle_normal/noticias/2720955/sociedad+salud/las-celulas-juegan-al-pilla-pilla-en-su-desa#.UcFgl-vomHk
http://earthsky.org/science-wire/cells-play-tag-to-determine-direction-of-movement
http://www.sciencedaily.com/releases/2013/06/130617092449.htm
http://www.newswhip.com/MoreInfo/Cells-play-tag-to-determine-direction-of/56232621
http://www.mediscuss.org/cells-play-tag-determine-direction-movement-33776/