TY  - BOOK
AU  - Rosenbaum Paul R
TI  - Observational studies
T2  - Springer series in statistics
SN  - 0387944826 (hbd)
U1  - B288, N5 
PY  - 1995///
CY  - New York    
PB  -  Springer        
KW  -  Experimental design
KW  - Statistics
N1  - Includes bibliographical references; Index 229-230p
ER  -