Un interesante artículo, publicado en 2014 de Jana Jones (Macquarie University, Sydney), Thomas F. G. Higham (University of Oxford, Oxford), Ron Oldfield (Macquarie University, Sydney), Terry P. O’Connor (University of York, The Kings Manor, York,), y Stephen A. Buckley (University of York, York)
Acceso: http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0103608