Sinauany-Stern Z and L Friedman (1998). ?DEA and the Discriminant Analysis of Ratios for Ranking Units.” EJOR 111(3): 470-478.

Singamsetti RN, PAVB Swamy and SB Taubman (1997). “A General Method of Deriving the Inefficiencies of Banks from a Profit Function.” JPA 8(1): 71-93.

Singer M, P Donoso and F Poblete (2002). “Semi-Autonomous Planning Using Linear Programming in the Chilean General Treasury.” EJOR 140(2): 517-529.

Singfat C, HT Keh and X Jiye (2006). “Efficiency, Effectiveness and Productivity of Marketing in Services.” EJOR 170(1): 265-276.

Singfat C-C-L (1998). “Bidding Efficiencies for Rights to Car Ownership in Singapore.” Omega 26(2): 297-306.

Simar L and PW Wilson (2007). “Estimation and Inference in Two-Stage, Semi-Parametric Models of Production Processes.” J Econometrics 136(1): 31-64.

Simar L and V Zelenyuk (2006). “On Testing Equality of Distributions of Technical Efficiency Scores.” Econometric Reviews 25(4): 497-522.

Simar Lo and P Wilson (2001). “Testing Restrictions in Nonparametric Efficiency Models.” Communications in Statistics: Simulation and Computation 30(1): 159.

Simar Lo and PW Wilson (2000). “A General Methodology for Bootstrapping in Non-Parametric Frontier Models.” J Applied Statistics 27(6): 779-802.

Sigler L (2004). “The Relative of the Public Institutions on Economics Research in Mexico City.” in Emrouznejad A and V Podinovski (eds.) Proceedings of DEA2004, Birmingham, UK: 386.