The unobservable factors that underpin the infant mortality gap between blacks and whites have persisted for more than 20 years and now appear to play a larger role than the observable factors, according to a new study.
Fuente : http://feeds.sciencedaily.com/~r/sciencedaily/~3/-...
Fuente : http://feeds.sciencedaily.com/~r/sciencedaily/~3/-...