Mathematical Programs with Complementarity Constraints: Stationarity, Optimality, and Sensitivity. - Holger Scheel; Stefan Scholtes (Math. Oper. Res., 2000)

Undesirable outputs in efficiency valuations. - Holger Scheel (Eur. J. Oper. Res., 2001)

Continuity of DEA Efficiency Measures. - Holger Scheel; Stefan Scholtes (Oper. Res., 2003)