APA
Heckman J. J., . (1999). Accounting for heterogeneity, diversity and general equilibrium in evaluating social programs. Cambridge, Mass: National Bureau of Economic Research.
Chicago
Heckman James J, . 1999. Accounting for heterogeneity, diversity and general equilibrium in evaluating social programs. Cambridge, Mass: National Bureau of Economic Research.
Harvard
Heckman J. J., . (1999). Accounting for heterogeneity, diversity and general equilibrium in evaluating social programs. Cambridge, Mass: National Bureau of Economic Research.
MLA
Heckman James J, . Accounting for heterogeneity, diversity and general equilibrium in evaluating social programs. Cambridge, Mass: National Bureau of Economic Research. 1999.