Simar L (2003). “Detecting Outliers in Frontier Models: A Simple Approach.” JPA 20(3): 391-424.

Simar L and PW Wilson (1998). “Sensitivity Analysis of Efficiency Scores: How to Bootstrap in Nonparametric Frontier Models.” Management Science 44(1): 49-61.

Simar L and PW Wilson (1999). “Estimating and Bootstrapping Malmquist Indices.” EJOR 115(3): 459-471.

Simar L and PW Wilson (2000). “Statistical Inference in Nonparametric Frontier Models: the State of the Art.” JPA 13(1): 49-78.

Simar L and PW Wilson (2002). “Non-Parametric Tests of Returns to Scale.” EJOR 139(1): 115-132.

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.

Silkman R and D Young (1982). “X-Efficiency and State Formula Grants.” National Tax Journal 35.

Silkman RH (1986). “Editor’s Notes: New Directions for Program Evaluation.” in Silkman RH (eds.) Measuring Efficiency: An Assessment of Data Envelopment Analysis, American Evaluation Association, Jossey Bass, Inc.

Silkman RH (1986). Measuring Efficiency: An Assessment of Data Envelopment Analysis. San Francisco, USA, Jossey-Bass.

Silva EG and JD Costa (2006). “Are Voters Rationally Ignorant? An Empirical Study of Portuguese Local Elections.” PORT ECON J 5(1): 31-44.