@unpublished{publication-10321,
	author={Balestra, Simone and Backes-Gellner, Uschi},
	institution={University of Zurich},
	number=102,
	series={Swiss Leading House "Economics of Education" Working Paper},
	title={Heterogeneous effects of pupil-to-teacher ratio policies – A look at class size reduction and teacher aide},
	year=2017,
}