共 122 条
[2]
[Anonymous], 1988, NEW ENGL J MED, V318, P262
[3]
[Anonymous], BROOKINGS PAPERS ED
[4]
[Anonymous], 1995, Identification Problems in the Social Sciences
[5]
[Anonymous], ANN AM ACAD POLITICA
[6]
[Anonymous], IMPLEMENTING RANDOMI
[7]
[Anonymous], 2002, Experimental and quasi-experimental designs for generalized causal inference
[8]
[Anonymous], 2003, ID IMPL ED PRACT SUP
[9]
[Anonymous], SOCIAL EXPT
[10]
[Anonymous], 2000, Evaluation Res. Ed.