title: "Deep" language disorders in nonfluent progressive Aphasia: an evaluation of the "summation" account of semantic errors across language production tasks.
authors.affiliation: University of Exeter, UK.
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Tree
authors.forename: Janice
authors.initials: J
authors.lastname: Kay
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Perfect