Hospital visitors as controls.
Armenian
H K
HK
Department of Epidemiology and Biostatistics, Faculty of Health Sciences, American University of Beirut, Lebanon.
Lakkis
N G
NG
Sibai
A M
AM
Halabi
S S
SS
D001943:Breast Neoplasms; D003327:Coronary Disease; D006801:Humans; D007861:Lebanon; D011897:Random Allocation; D012494:Sampling Studies; D014789:Visitors to Patients