共 39 条
[2]
[Anonymous], 2002, Experimental and quasi-experimental designs for generalized causal inference
[3]
[Anonymous], AM J MANAG CARE
[5]
BURTON W, 1999, BUS HEALTH, P34
[7]
Economic and social impact of migraine
[J].
QJM-MONTHLY JOURNAL OF THE ASSOCIATION OF PHYSICIANS,
1996, 89 (01)
:77-84
[8]
Cohen J A, 1996, Fam Med, V28, P171