Author
National Center for Health Statistics (U.S.),
2
Brett, K. M.
1
Burt, Catharine W.,
1
Hudson, Bettie L.,
1
National Ambulatory Medical Care Survey (U.S.)
1
National Health Care Survey (U.S.)
1
National Hospital Ambulatory Medical Care Survey (U.S.)
1
United States. Health Resources and Services Administration
1
United States. Maternal and Child Health Bureau
1