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A review of propensity score: Principles, methods, and application in Stata
Grotta, Alessandra, (2014)
Goodness-of-fit tests for categorical data: Comparing Stata, R, and SAS
Bellocco, Rino, (2011)
Analysis of Longitudinal Data in Stata, Splus and SAS
Bellocco, Rino, (2001)