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Influential observations in frontier models, a robust non-oriented approach to the water sector
De Witte, Kristof, (2010)
Is big better? : on scale and scope economies in the Portuguese water sector
Marques, Rui Cunha, (2011)
Big and beautiful? : on non-parametrically measuring scale economies in non-convex technologies
De Witte, Kristof, (2011)