http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
National Ambulatory Medical Care Survey: background and methodology
National Center for Health Statistics (U.S.)
James B. Tenney, Kerr L. White, and John W. Williamson.
"Prepared for the Division of Health Resources Statistics, National Center for Health Statistics."
Includes bibliographical references (page 19).
National Ambulatory Medical Care Survey (U.S.)