Try these two http://www-personal.umich.edu/~wmebane/apsa09.pdf http://www-personal.umich.edu/~wmebane/mw10B.pdf fraud methods don't vary from election to election.
Try these two http://www-personal.umich.edu/~wmebane/apsa09.pdf http://www-personal.umich.edu/~wmebane/mw10B.pdf fraud methods don't vary from election to election.