//-->
Non-convex Technologies and Cost Functions : definitions, Duality and Nonparametric Tests of Convexity
Briec, Walter, (2004)
Returns to Scale on Nonparametric Deterministic Technologies: Simplifying Goodness-of-Fit Methods Using Operations on Technologies
Briec, Walter, (2000)
A new criterion for technical efficiency measures: non-monotonicity across dimensions axioms
Kerstens, Kristiaan, (1999)