RT Journal Article SR Electronic T1 Online-only: Nation’s premature birth rate improving, but not enough to make the grade JF The Nation's Health JO Nations Health FD American Public Health Association SP E48 OP E48 VO 40 IS 10 A1 Teddi Dineley Johnson YR 2011 UL http://www.thenationshealth.org/content/40/10/E48.abstract AB