title: To what extent do environmental factors contribute to the occurrence of autism spectrum disorders?
authors.affiliation: Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy.
authors.forename: Annio
authors.initials: A
authors.lastname: Posar
authors.affiliation: Child Neurology and Psychiatry Unit, IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Visconti