@unpublished{publication-5859,
	author={Filippini, Massimo and Wild, J{\"o}rg},
	institution={University of Zurich},
	number={No. 9803},
	series={Working paper series / Socioeconomic Institute},
	title={The Estimation of an Average Cost Frontier to Calculate Benchmark Tariffs for Electricity Distribution},
	year=1998,
}